A question about boat weight and displacement
 

I am having trouble attempting to determine the weight of a
boat, with limited information about it. The purpose of this
inquiry is to reach a definitive answer to whether or not a
vessel is trailerable, and if so, what sort of vehicle will
be needed to tow it.

I am hoping to be able to reach an educated guess about the
general weight of the vessel, with limited information and
knowledge about the boat. I am not attempting to make any
determination of any specific weight, just a ball-park guess.

Here is the information I have on this vessel:

Hull Material: Wood
LOA: 28'
Beam: 10'-6"
Displacement: 6,075 lbs
Draft: 2'-2"

Is it possible to determine how much this vessel weighs from
this sort of information? If not, what other information would
I need to determine the weight of this vessel, and then to add
in gear, trailer, etc. to determine what vehicle I would need
with which to pull it?

One other question: How does one go about obtaining a trailer
for a boat that does not have one?

Thank you.

---
-
A. Topic Mimara
Unique in the World! You will appreciate!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

Just give the DOT a call. They can tell you the bottom line instantly.
10'6" is definately wide for towing, but I don't think it is wider than
a standard tractor-trailer. Non of this has anything to do with
weight and displacement though.

Doug
s/v Callista

wrote in message
...
On 1 Apr 2004 01:27:50 -0000, Ante Topic Mimara
] wrote:

I am having trouble attempting to determine the weight of a
boat, with limited information about it.
[snip]

Here is the information I have on this vessel:

Hull Material: Wood
LOA: 28'
Beam: 10'-6"
Displacement: 6,075 lbs
Draft: 2'-2"

With a beam of 10' 6" won't you will be towing an oversize load which will
require a special permit and special arrangments each time that you tow
this
boat only during daylight hours?

A question about boat weight and displacement
 

Just give the DOT a call. They can tell you the bottom line instantly.
10'6" is definately wide for towing, but I don't think it is wider than
a standard tractor-trailer. Non of this has anything to do with
weight and displacement though.

Doug
s/v Callista

wrote in message
...
On 1 Apr 2004 01:27:50 -0000, Ante Topic Mimara
] wrote:

I am having trouble attempting to determine the weight of a
boat, with limited information about it.
[snip]

Here is the information I have on this vessel:

Hull Material: Wood
LOA: 28'
Beam: 10'-6"
Displacement: 6,075 lbs
Draft: 2'-2"

With a beam of 10' 6" won't you will be towing an oversize load which will
require a special permit and special arrangments each time that you tow
this
boat only during daylight hours?

A question about boat weight and displacement
 

As far as I know displacement = weight. Certainly the weight of the boat will
displace the amount of water with that same weight (hence the term
displacement). That said, for documentation purposes the Coast Guard refers to
a tonnage (don't recall if they call it displacement) that relates only to boat
volume, not the weight.

A question about boat weight and displacement
 

As far as I know displacement = weight. Certainly the weight of the boat will
displace the amount of water with that same weight (hence the term
displacement). That said, for documentation purposes the Coast Guard refers to
a tonnage (don't recall if they call it displacement) that relates only to boat
volume, not the weight.

A question about boat weight and displacement
 

In article 2MRDDW2938077.852662037@anonymous,
Ante Topic Mimara ] wrote:

I am having trouble attempting to determine the weight of a
boat, with limited information about it. snip
Displacement: 6,075 lbs
Draft: 2'-2"

Is it possible to determine how much this vessel weighs from
this sort of information?

As it happens, we're about 1000# heavier and about the same size, though
taller. A couple of Xan's sisters are hauled on trailers, but not often.
Pretty much one round trip a year.

Expect your weight and displacement to be roughly equivalent. Add a
trailor and gear you're in the 7-8000# range, possibly higher. You're
talking a pretty good-sized tow vehicle and a fairly expensive trailer
unless you can adapt a used one. [If you have a cradle, it can be
secured to a flat bed, BTW.] As I recall, I was told a 150 with a tow
package can handle it in a pinch, but a 250 is better.

Splashing and retrieving the boat in can be a hassle, but you might be
able to float it off and on at a good ramp. Otherwise, you'll need a
hoist/lift. If you have a wooden mast, add the use of a crane.

All these things cost. When I ran the numbers, I found I could pay a
professional to haul it back and forth each season for years and years
before matching the initial outlay on the towing equipment. Was even
cheaper to let the marina haul and store.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

A question about boat weight and displacement
 

In article 2MRDDW2938077.852662037@anonymous,
Ante Topic Mimara ] wrote:

I am having trouble attempting to determine the weight of a
boat, with limited information about it. snip
Displacement: 6,075 lbs
Draft: 2'-2"

Is it possible to determine how much this vessel weighs from
this sort of information?

As it happens, we're about 1000# heavier and about the same size, though
taller. A couple of Xan's sisters are hauled on trailers, but not often.
Pretty much one round trip a year.

Expect your weight and displacement to be roughly equivalent. Add a
trailor and gear you're in the 7-8000# range, possibly higher. You're
talking a pretty good-sized tow vehicle and a fairly expensive trailer
unless you can adapt a used one. [If you have a cradle, it can be
secured to a flat bed, BTW.] As I recall, I was told a 150 with a tow
package can handle it in a pinch, but a 250 is better.

Splashing and retrieving the boat in can be a hassle, but you might be
able to float it off and on at a good ramp. Otherwise, you'll need a
hoist/lift. If you have a wooden mast, add the use of a crane.

All these things cost. When I ran the numbers, I found I could pay a
professional to haul it back and forth each season for years and years
before matching the initial outlay on the towing equipment. Was even
cheaper to let the marina haul and store.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

A question about boat weight and displacement
 

As far as I know displacement = weight. Certainly the weight of the boat
will
displace the amount of water with that same weight (hence the term
displacement). That said, for documentation purposes the Coast Guard refers
to
a tonnage (don't recall if they call it displacement) that relates only to
boat
volume, not the weight.

Although not as common as a reference to cubic volume, calculating the weight
of a vessel is an uncommon but still correct use for the term tonnage.

When speaking of volume, gross tonnage is the total amount of space contained
within the hull, divided into 100 cubic foot portions. Net tonnage is the total
volume, less the space taken up by engines, generators, fuel tanks, etc.

A boat with 1000 cubic feet of open area where cargo could, theoretically, be
carried
would be rated at 10 net tons. Would have nothing to do with that vessel
weighing 20,000 pounds.......which unless by sheer
happenstance it probably would not.

Then it gets a bit trickier yet. In many cases a "ton" refers to a "long ton"
of 2240 pounds.

Undoubtedly some young woman once who got pretty drunk, was slurring her
speech, and started fantasizing about looking for man who was a good kisser
with a "long ton"......
have to wonder if she would have thought a long ton was so desirable if it came
attached to a guy who weighed 2240 pounds. :-)

A question about boat weight and displacement
 

As far as I know displacement = weight. Certainly the weight of the boat
will
displace the amount of water with that same weight (hence the term
displacement). That said, for documentation purposes the Coast Guard refers
to
a tonnage (don't recall if they call it displacement) that relates only to
boat
volume, not the weight.

Although not as common as a reference to cubic volume, calculating the weight
of a vessel is an uncommon but still correct use for the term tonnage.

When speaking of volume, gross tonnage is the total amount of space contained
within the hull, divided into 100 cubic foot portions. Net tonnage is the total
volume, less the space taken up by engines, generators, fuel tanks, etc.

A boat with 1000 cubic feet of open area where cargo could, theoretically, be
carried
would be rated at 10 net tons. Would have nothing to do with that vessel
weighing 20,000 pounds.......which unless by sheer
happenstance it probably would not.

Then it gets a bit trickier yet. In many cases a "ton" refers to a "long ton"
of 2240 pounds.

Undoubtedly some young woman once who got pretty drunk, was slurring her
speech, and started fantasizing about looking for man who was a good kisser
with a "long ton"......
have to wonder if she would have thought a long ton was so desirable if it came
attached to a guy who weighed 2240 pounds. :-)

A question about boat weight and displacement
 

A question about boat weight and displacement
 

DUINK writes:

As far as I know displacement = weight.

Somehow, this doesn't sound right to me.

Certainly the weight of the boat will displace the amount of
water with that same weight (hence the term displacement).

If something displaces X pounds of water, it must weigh X - n to
be able to float. It must weigh less than the amount of water it
displaces, else it will have neutral (or worse, negative) buoyancy.

Having said this, how do I determine how much it weighs, from
limited information, without being there to weigh it?

That said, for documentation purposes the Coast Guard refers to
a tonnage (don't recall if they call it displacement) that relates
only to boat volume, not the weight.

This is very interesting. It also has nothing to do with what I
asked originally. I cannot see inquiring of the Coast Guard about
the tonnage or volume of a 28 foot motor boat. What can they tell
me about how much this vessel weighs, by me inquiring about the
volume of the boat?

I do not understand where you were going with this.

Do you have anything to add that will address the original question?

---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

DUINK writes:

As far as I know displacement = weight.

Somehow, this doesn't sound right to me.

Certainly the weight of the boat will displace the amount of
water with that same weight (hence the term displacement).

If something displaces X pounds of water, it must weigh X - n to
be able to float. It must weigh less than the amount of water it
displaces, else it will have neutral (or worse, negative) buoyancy.

Having said this, how do I determine how much it weighs, from
limited information, without being there to weigh it?

That said, for documentation purposes the Coast Guard refers to
a tonnage (don't recall if they call it displacement) that relates
only to boat volume, not the weight.

This is very interesting. It also has nothing to do with what I
asked originally. I cannot see inquiring of the Coast Guard about
the tonnage or volume of a 28 foot motor boat. What can they tell
me about how much this vessel weighs, by me inquiring about the
volume of the boat?

I do not understand where you were going with this.

Do you have anything to add that will address the original question?

---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

Doug Dotson writes:

Just give the DOT a call.

DOT? This is Federal Department of Transportation, and not for
a single State, I presume?

They can tell you the bottom line instantly.

Fantastic idea! Thank you!

10'6" is definately wide for towing, but I don't think it is
wider than a standard tractor-trailer.

Truthfully, this width thing never occurred to me.

None of this has anything to do with weight and displacement
though.

Yes, it doesn't. Can you add anything to address this question?
Thank you so much for your other information.
---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

Doug Dotson writes:

Just give the DOT a call.

DOT? This is Federal Department of Transportation, and not for
a single State, I presume?

They can tell you the bottom line instantly.

Fantastic idea! Thank you!

10'6" is definately wide for towing, but I don't think it is
wider than a standard tractor-trailer.

Truthfully, this width thing never occurred to me.

None of this has anything to do with weight and displacement
though.

Yes, it doesn't. Can you add anything to address this question?
Thank you so much for your other information.
---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

DUINK writes:

As far as I know displacement = weight.

Somehow, this doesn't sound right to me.

Certainly the weight of the boat will displace the amount of
water with that same weight (hence the term displacement).

If something displaces X pounds of water, it must weigh X - n to
be able to float. It must weigh less than the amount of water it
displaces, else it will have neutral (or worse, negative) buoyancy.

Having said this, how do I determine how much it weighs, from
limited information, without being there to weigh it?

That said, for documentation purposes the Coast Guard refers to
a tonnage (don't recall if they call it displacement) that relates
only to boat volume, not the weight.

This is very interesting. It also has nothing to do with what I
asked originally. I cannot see inquiring of the Coast Guard about
the tonnage or volume of a 28 foot motor boat. What can they tell
me about how much this vessel weighs, by me inquiring about the
volume of the boat?

I do not understand where you were going with this.

Do you have anything to add that will address the original question?

---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

DUINK writes:

As far as I know displacement = weight.

Somehow, this doesn't sound right to me.

Certainly the weight of the boat will displace the amount of
water with that same weight (hence the term displacement).

If something displaces X pounds of water, it must weigh X - n to
be able to float. It must weigh less than the amount of water it
displaces, else it will have neutral (or worse, negative) buoyancy.

Having said this, how do I determine how much it weighs, from
limited information, without being there to weigh it?

That said, for documentation purposes the Coast Guard refers to
a tonnage (don't recall if they call it displacement) that relates
only to boat volume, not the weight.

This is very interesting. It also has nothing to do with what I
asked originally. I cannot see inquiring of the Coast Guard about
the tonnage or volume of a 28 foot motor boat. What can they tell
me about how much this vessel weighs, by me inquiring about the
volume of the boat?

I do not understand where you were going with this.

Do you have anything to add that will address the original question?

---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

Jere Lull writes:

Ante Topic Mimara wrote:

I am having trouble attempting to determine the weight of
a boat, with limited information about it. snip
Displacement: 6,075 lbs
Draft: 2'-2"

Is it possible to determine how much this vessel weighs from
this sort of information?

As it happens, we're about 1000# heavier and about the same size,
though taller. A couple of Xan's sisters are hauled on trailers,
but not often. Pretty much one round trip a year.

What kind of motor boat do you have?

Expect your weight and displacement to be roughly equivalent.

Would this not be the same thing as the neutral buoyancy issue?

Add a trailer and gear you're in the 7-8000# range, possibly
higher.

Yes, I can see that adding a trailer will add some weight. I
was just hoping to get some idea of how much, in addition to
determining the weight of the boat as well.

You're talking a pretty good-sized tow vehicle and a fairly
expensive trailer unless you can adapt a used one.

I do not know if a trailer is available, so I assume not. I
believe I will have to have one made, if I can find out what
the weight of the vessel is.

[If you have a cradle, it can be secured to a flat bed, BTW.]

What is a "cradle" as it applies to boat trailers? I have never
seen any other kind of boat trailer that the boat does anything
but sit on top of the trailer. Is this something I must add, for
safety or travel?

As I recall, I was told a 150 with a tow package can handle
it in a pinch, but a 250 is better.

I'm totally lost here. To what kind of vehicles do you refer?

Splashing and retrieving the boat in can be a hassle, but you
might be able to float it off and on at a good ramp.

All of the boats I have seen people back into the lakes and river
around here, just back up, and the boat floats off the trailer.

Is there another way of doing it that I do not know about?

Otherwise, you'll need a hoist/lift.

I am not familiar with this.

If you have a wooden mast, add the use of a crane.

Mast? There is no mast on this boat. It is a 28 foot long
Grandy Sedan Cruiser. It has no masts that I know of.

All these things cost. When I ran the numbers, I found I could
pay a professional to haul it back and forth each season for
years and years before matching the initial outlay on the towing
equipment. Was even cheaper to let the marina haul and store.

I deeply appreciate your writing all you did, but it does not mean
anything to me. I do not know about many of these things to which
you refer.

I just want to find out if it is feasible to be able to move this
boat between the river and the lakes around here, or take it to
the coast on a trailer (150 miles) so that I can go up and down
the coast, without following the river to the coast (220 miles)
on a trailer.

Thanks for all the other information though!

---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

Jere Lull writes:

Ante Topic Mimara wrote:

I am having trouble attempting to determine the weight of
a boat, with limited information about it. snip
Displacement: 6,075 lbs
Draft: 2'-2"

Is it possible to determine how much this vessel weighs from
this sort of information?

As it happens, we're about 1000# heavier and about the same size,
though taller. A couple of Xan's sisters are hauled on trailers,
but not often. Pretty much one round trip a year.

What kind of motor boat do you have?

Expect your weight and displacement to be roughly equivalent.

Would this not be the same thing as the neutral buoyancy issue?

Add a trailer and gear you're in the 7-8000# range, possibly
higher.

Yes, I can see that adding a trailer will add some weight. I
was just hoping to get some idea of how much, in addition to
determining the weight of the boat as well.

You're talking a pretty good-sized tow vehicle and a fairly
expensive trailer unless you can adapt a used one.

I do not know if a trailer is available, so I assume not. I
believe I will have to have one made, if I can find out what
the weight of the vessel is.

[If you have a cradle, it can be secured to a flat bed, BTW.]

What is a "cradle" as it applies to boat trailers? I have never
seen any other kind of boat trailer that the boat does anything
but sit on top of the trailer. Is this something I must add, for
safety or travel?

As I recall, I was told a 150 with a tow package can handle
it in a pinch, but a 250 is better.

I'm totally lost here. To what kind of vehicles do you refer?

Splashing and retrieving the boat in can be a hassle, but you
might be able to float it off and on at a good ramp.

All of the boats I have seen people back into the lakes and river
around here, just back up, and the boat floats off the trailer.

Is there another way of doing it that I do not know about?

Otherwise, you'll need a hoist/lift.

I am not familiar with this.

If you have a wooden mast, add the use of a crane.

Mast? There is no mast on this boat. It is a 28 foot long
Grandy Sedan Cruiser. It has no masts that I know of.

All these things cost. When I ran the numbers, I found I could
pay a professional to haul it back and forth each season for
years and years before matching the initial outlay on the towing
equipment. Was even cheaper to let the marina haul and store.

I deeply appreciate your writing all you did, but it does not mean
anything to me. I do not know about many of these things to which
you refer.

I just want to find out if it is feasible to be able to move this
boat between the river and the lakes around here, or take it to
the coast on a trailer (150 miles) so that I can go up and down
the coast, without following the river to the coast (220 miles)
on a trailer.

Thanks for all the other information though!

---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

Doug Dotson writes:

Just give the DOT a call.

DOT? This is Federal Department of Transportation, and not for
a single State, I presume?

They can tell you the bottom line instantly.

Fantastic idea! Thank you!

10'6" is definately wide for towing, but I don't think it is
wider than a standard tractor-trailer.

Truthfully, this width thing never occurred to me.

None of this has anything to do with weight and displacement
though.

Yes, it doesn't. Can you add anything to address this question?
Thank you so much for your other information.
---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

Doug Dotson writes:

Just give the DOT a call.

DOT? This is Federal Department of Transportation, and not for
a single State, I presume?

They can tell you the bottom line instantly.

Fantastic idea! Thank you!

10'6" is definately wide for towing, but I don't think it is
wider than a standard tractor-trailer.

Truthfully, this width thing never occurred to me.

None of this has anything to do with weight and displacement
though.

Yes, it doesn't. Can you add anything to address this question?
Thank you so much for your other information.
---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

On 1 Apr 2004 14:14:21 -0000, Ante Topic Mimara
] wrote:

DUINK writes:

As far as I know displacement = weight.

Somehow, this doesn't sound right to me.

Certainly the weight of the boat will displace the amount of
water with that same weight (hence the term displacement).

If something displaces X pounds of water, it must weigh X - n to
be able to float. It must weigh less than the amount of water it
displaces, else it will have neutral (or worse, negative) buoyancy.

This is Archimedes principle

"a body immersed in a fluid is buoyed up by a force equal to the
weight of the displaced fluid."

http://www.infoplease.com/ce6/sci/A0804583.html

Having said this, how do I determine how much it weighs, from
limited information, without being there to weigh it?

Displacement equals weight.

Jack

__________________________________________________
Jack Dale
Swiftsure Sailing Academy
Director
ISPA and CYA Instructor
http://www.swiftsuresailing.com
Phone: 1 (877) 470-SAIL (toll free)
__________________________________________________

A question about boat weight and displacement
 

On 1 Apr 2004 14:14:21 -0000, Ante Topic Mimara
] wrote:

DUINK writes:

As far as I know displacement = weight.

Somehow, this doesn't sound right to me.

Certainly the weight of the boat will displace the amount of
water with that same weight (hence the term displacement).

If something displaces X pounds of water, it must weigh X - n to
be able to float. It must weigh less than the amount of water it
displaces, else it will have neutral (or worse, negative) buoyancy.

This is Archimedes principle

"a body immersed in a fluid is buoyed up by a force equal to the
weight of the displaced fluid."

http://www.infoplease.com/ce6/sci/A0804583.html

Having said this, how do I determine how much it weighs, from
limited information, without being there to weigh it?

Displacement equals weight.

Jack

__________________________________________________
Jack Dale
Swiftsure Sailing Academy
Director
ISPA and CYA Instructor
http://www.swiftsuresailing.com
Phone: 1 (877) 470-SAIL (toll free)
__________________________________________________

A question about boat weight and displacement
 

"Doug Dotson" wrote ...
Just give the DOT a call. They can tell you the bottom line instantly.
10'6" is definately wide for towing, but I don't think it is wider than
a standard tractor-trailer.


legal width (standard trailer) = 8' 6''
anything more than that, you need permits.

SV

A question about boat weight and displacement
 

"Doug Dotson" wrote ...
Just give the DOT a call. They can tell you the bottom line instantly.
10'6" is definately wide for towing, but I don't think it is wider than
a standard tractor-trailer.


legal width (standard trailer) = 8' 6''
anything more than that, you need permits.

SV

A question about boat weight and displacement
 

No. Each state has it's own , sometimes unique, rules (laws).

What state(s) are you asking about?

SV

"Ante Topic Mimara" ] wrote in message
news:ALSJDPK238078.3918865741@anonymous...
Doug Dotson writes:

Just give the DOT a call.

DOT? This is Federal Department of Transportation, and not for
a single State, I presume?

They can tell you the bottom line instantly.

Fantastic idea! Thank you!

10'6" is definately wide for towing, but I don't think it is
wider than a standard tractor-trailer.

Truthfully, this width thing never occurred to me.

None of this has anything to do with weight and displacement
though.

Yes, it doesn't. Can you add anything to address this question?
Thank you so much for your other information.
---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

No. Each state has it's own , sometimes unique, rules (laws).

What state(s) are you asking about?

SV

"Ante Topic Mimara" ] wrote in message
news:ALSJDPK238078.3918865741@anonymous...
Doug Dotson writes:

Just give the DOT a call.

DOT? This is Federal Department of Transportation, and not for
a single State, I presume?

They can tell you the bottom line instantly.

Fantastic idea! Thank you!

10'6" is definately wide for towing, but I don't think it is
wider than a standard tractor-trailer.

Truthfully, this width thing never occurred to me.

None of this has anything to do with weight and displacement
though.

Yes, it doesn't. Can you add anything to address this question?
Thank you so much for your other information.
---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

As far as I know displacement = weight.


Ante Topic Mimara said:
Somehow, this doesn't sound right to me.

Dave wrote:
It is.

Sorry to disagree yet again, but it's not that simple. It depends very
much on whose figures for displacemnt you are using, and their intent.

The designers figure for displacement will be the boat's intended
immersed volume, converted to units of weight since water density is
relatively consistent. This will include the boat & all it's parts... it
usually but not always includes full water & fuel tanks, crew, and some
amount of supplies. In other words, the boats actual weight when in use.

The builders figure for displacement can be the same as the designers,
or it could be the actual weight of the boat as built, plus a
guesstimate of how much "stuff" it can reasonably be loaded with for
sailing... or it could be a fantasy intended to create a false
impression of good performance on potential buyers. Lots of times
builders start changing the design and end up with a boat that is
substnatially heavier than the designer intended.

Sometimes a "half-load" displacement is quoted, meaning what the boat
would weigh in the middle of a cruise.

In any event, since the post is intending to trailer the boat and needs
an accurate number for that purpose, it would be a really good idea to
simply weigh the thing. The displacement figure would be a good starting
guess, but it won't put Humpty Dumpty back together again if it turns
out to be wrong by a lot.

FB
Doug King

A question about boat weight and displacement
 

As far as I know displacement = weight.


Ante Topic Mimara said:
Somehow, this doesn't sound right to me.

Dave wrote:
It is.

Sorry to disagree yet again, but it's not that simple. It depends very
much on whose figures for displacemnt you are using, and their intent.

The designers figure for displacement will be the boat's intended
immersed volume, converted to units of weight since water density is
relatively consistent. This will include the boat & all it's parts... it
usually but not always includes full water & fuel tanks, crew, and some
amount of supplies. In other words, the boats actual weight when in use.

The builders figure for displacement can be the same as the designers,
or it could be the actual weight of the boat as built, plus a
guesstimate of how much "stuff" it can reasonably be loaded with for
sailing... or it could be a fantasy intended to create a false
impression of good performance on potential buyers. Lots of times
builders start changing the design and end up with a boat that is
substnatially heavier than the designer intended.

Sometimes a "half-load" displacement is quoted, meaning what the boat
would weigh in the middle of a cruise.

In any event, since the post is intending to trailer the boat and needs
an accurate number for that purpose, it would be a really good idea to
simply weigh the thing. The displacement figure would be a good starting
guess, but it won't put Humpty Dumpty back together again if it turns
out to be wrong by a lot.

FB
Doug King

A question about boat weight and displacement
 

Having said this, how do I determine how much it weighs, from
limited information, without being there to weigh it?

You can't. The dimensions (alone) of the boat don't dictate the weight. It's a
wooden hull......ok, how thick? Low deadrise or deep V? 1000 pounds of gear
aboard, or not? Way too many variables.

Figure that with the trailer it will be at least as heavy as the "displacement"
number plus the curb weight of the empty trailer. At least.

A question about boat weight and displacement
 

Having said this, how do I determine how much it weighs, from
limited information, without being there to weigh it?

You can't. The dimensions (alone) of the boat don't dictate the weight. It's a
wooden hull......ok, how thick? Low deadrise or deep V? 1000 pounds of gear
aboard, or not? Way too many variables.

Figure that with the trailer it will be at least as heavy as the "displacement"
number plus the curb weight of the empty trailer. At least.

A question about boat weight and displacement
 

I beleive that "tonnage" is not directly related to displacement but
rather the internal volume of the boat that is usable to carry cargo.
Something like that. Anyway, the tonnage of my boat is quite a bit different
than the displacement.

The OP started the post by referring to weight (displacement), but the
final question seemed to be more related to the width of the trailered
boat.

Doug
s/v Callista

"DUINK" wrote in message
...
As far as I know displacement = weight. Certainly the weight of the boat
will
displace the amount of water with that same weight (hence the term
displacement). That said, for documentation purposes the Coast Guard
refers to
a tonnage (don't recall if they call it displacement) that relates only to
boat
volume, not the weight.

A question about boat weight and displacement
 

I beleive that "tonnage" is not directly related to displacement but
rather the internal volume of the boat that is usable to carry cargo.
Something like that. Anyway, the tonnage of my boat is quite a bit different
than the displacement.

The OP started the post by referring to weight (displacement), but the
final question seemed to be more related to the width of the trailered
boat.

Doug
s/v Callista

"DUINK" wrote in message
...
As far as I know displacement = weight. Certainly the weight of the boat
will
displace the amount of water with that same weight (hence the term
displacement). That said, for documentation purposes the Coast Guard
refers to
a tonnage (don't recall if they call it displacement) that relates only to
boat
volume, not the weight.

A question about boat weight and displacement
 

Jere Lull writes:

Ante Topic Mimara wrote:

I am having trouble attempting to determine the weight of
a boat, with limited information about it. snip
Displacement: 6,075 lbs
Draft: 2'-2"

Is it possible to determine how much this vessel weighs from
this sort of information?

As it happens, we're about 1000# heavier and about the same size,
though taller. A couple of Xan's sisters are hauled on trailers,
but not often. Pretty much one round trip a year.

What kind of motor boat do you have?

Expect your weight and displacement to be roughly equivalent.

Would this not be the same thing as the neutral buoyancy issue?

Add a trailer and gear you're in the 7-8000# range, possibly
higher.

Yes, I can see that adding a trailer will add some weight. I
was just hoping to get some idea of how much, in addition to
determining the weight of the boat as well.

You're talking a pretty good-sized tow vehicle and a fairly
expensive trailer unless you can adapt a used one.

I do not know if a trailer is available, so I assume not. I
believe I will have to have one made, if I can find out what
the weight of the vessel is.

[If you have a cradle, it can be secured to a flat bed, BTW.]

What is a "cradle" as it applies to boat trailers? I have never
seen any other kind of boat trailer that the boat does anything
but sit on top of the trailer. Is this something I must add, for
safety or travel?

As I recall, I was told a 150 with a tow package can handle
it in a pinch, but a 250 is better.

I'm totally lost here. To what kind of vehicles do you refer?

Splashing and retrieving the boat in can be a hassle, but you
might be able to float it off and on at a good ramp.

All of the boats I have seen people back into the lakes and river
around here, just back up, and the boat floats off the trailer.

Is there another way of doing it that I do not know about?

Otherwise, you'll need a hoist/lift.

I am not familiar with this.

If you have a wooden mast, add the use of a crane.

Mast? There is no mast on this boat. It is a 28 foot long
Grandy Sedan Cruiser. It has no masts that I know of.

All these things cost. When I ran the numbers, I found I could
pay a professional to haul it back and forth each season for
years and years before matching the initial outlay on the towing
equipment. Was even cheaper to let the marina haul and store.

I deeply appreciate your writing all you did, but it does not mean
anything to me. I do not know about many of these things to which
you refer.

I just want to find out if it is feasible to be able to move this
boat between the river and the lakes around here, or take it to
the coast on a trailer (150 miles) so that I can go up and down
the coast, without following the river to the coast (220 miles)
on a trailer.

Thanks for all the other information though!

---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

Jere Lull writes:

Ante Topic Mimara wrote:

I am having trouble attempting to determine the weight of
a boat, with limited information about it. snip
Displacement: 6,075 lbs
Draft: 2'-2"

Is it possible to determine how much this vessel weighs from
this sort of information?

As it happens, we're about 1000# heavier and about the same size,
though taller. A couple of Xan's sisters are hauled on trailers,
but not often. Pretty much one round trip a year.

What kind of motor boat do you have?

Expect your weight and displacement to be roughly equivalent.

Would this not be the same thing as the neutral buoyancy issue?

Add a trailer and gear you're in the 7-8000# range, possibly
higher.

Yes, I can see that adding a trailer will add some weight. I
was just hoping to get some idea of how much, in addition to
determining the weight of the boat as well.

You're talking a pretty good-sized tow vehicle and a fairly
expensive trailer unless you can adapt a used one.

I do not know if a trailer is available, so I assume not. I
believe I will have to have one made, if I can find out what
the weight of the vessel is.

[If you have a cradle, it can be secured to a flat bed, BTW.]

What is a "cradle" as it applies to boat trailers? I have never
seen any other kind of boat trailer that the boat does anything
but sit on top of the trailer. Is this something I must add, for
safety or travel?

As I recall, I was told a 150 with a tow package can handle
it in a pinch, but a 250 is better.

I'm totally lost here. To what kind of vehicles do you refer?

Splashing and retrieving the boat in can be a hassle, but you
might be able to float it off and on at a good ramp.

All of the boats I have seen people back into the lakes and river
around here, just back up, and the boat floats off the trailer.

Is there another way of doing it that I do not know about?

Otherwise, you'll need a hoist/lift.

I am not familiar with this.

If you have a wooden mast, add the use of a crane.

Mast? There is no mast on this boat. It is a 28 foot long
Grandy Sedan Cruiser. It has no masts that I know of.

All these things cost. When I ran the numbers, I found I could
pay a professional to haul it back and forth each season for
years and years before matching the initial outlay on the towing
equipment. Was even cheaper to let the marina haul and store.

I deeply appreciate your writing all you did, but it does not mean
anything to me. I do not know about many of these things to which
you refer.

I just want to find out if it is feasible to be able to move this
boat between the river and the lakes around here, or take it to
the coast on a trailer (150 miles) so that I can go up and down
the coast, without following the river to the coast (220 miles)
on a trailer.

Thanks for all the other information though!

---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

Doug Dotson writes:

Just give the DOT a call.

DOT? This is Federal Department of Transportation, and not for
a single State, I presume?

They can tell you the bottom line instantly.

Fantastic idea! Thank you!

10'6" is definately wide for towing, but I don't think it is
wider than a standard tractor-trailer.

Truthfully, this width thing never occurred to me.

None of this has anything to do with weight and displacement
though.

Yes, it doesn't. Can you add anything to address this question?
Thank you so much for your other information.
---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

Doug Dotson writes:

Just give the DOT a call.

DOT? This is Federal Department of Transportation, and not for
a single State, I presume?

They can tell you the bottom line instantly.

Fantastic idea! Thank you!

10'6" is definately wide for towing, but I don't think it is
wider than a standard tractor-trailer.

Truthfully, this width thing never occurred to me.

None of this has anything to do with weight and displacement
though.

Yes, it doesn't. Can you add anything to address this question?
Thank you so much for your other information.
---
-
Topic-Mimara
Unique in the World!
---


-=-
This message was posted via two or more anonymous remailing services.

A question about boat weight and displacement
 

In article LKDGRCFC38078.9701851852@anonymous,
Ante Topic Mimara ] wrote:

Jere Lull writes:

Ante Topic Mimara wrote:

I am having trouble attempting to determine the weight of
a boat, with limited information about it. snip
Displacement: 6,075 lbs
Draft: 2'-2"

Is it possible to determine how much this vessel weighs from
this sort of information?

As it happens, we're about 1000# heavier and about the same size,
though taller. A couple of Xan's sisters are hauled on trailers,
but not often. Pretty much one round trip a year.

What kind of motor boat do you have?

She's a sailboat (see her page below). Her displacement -- and weight --
is nearly 1000# higher than what you have listed. As I said before, she
can be towed, but it requires a big truck.

Add a trailer and gear you're in the 7-8000# range, possibly
higher.

Yes, I can see that adding a trailer will add some weight. I
was just hoping to get some idea of how much, in addition to
determining the weight of the boat as well.

If the 6075# you quoted is correct, I'd say you'd be safe if you chose
8000# for a working number. Planning for 10,000 would possibly be safer,
but I am pretty sure everything would add up to less than that.

What is a "cradle" as it applies to boat trailers?

It's a custom frame to hold the boat safely while it's on land.
Sometimes a boat will have one, but if you haven't heard the term,
you'll probably have to get/buy/build a trailer.

As I recall, I was told a 150 with a tow package can handle
it in a pinch, but a 250 is better.

I'm totally lost here. To what kind of vehicles do you refer?

Sorry. They're the largest pickup trucks, built for heavy use. Take a
look at trucks rated to tow -- and stop -- 8-10,000 pounds.

All of the boats I have seen people back into the lakes and river
around here, just back up, and the boat floats off the trailer.
Is there another way of doing it that I do not know about?

There are other ways, but if the boat actually draws only 2'2", you
probably will be able to float off as they do, so there's no need to get
into that.

I just want to find out if it is feasible to be able to move this
boat between the river and the lakes around here, or take it to
the coast on a trailer (150 miles) so that I can go up and down
the coast, without following the river to the coast (220 miles)
on a trailer.

Ahhh! Intended use comes out!

It's feasible, most likely, but those are fairly long distances. I towed
for a decade and enjoyed playing on waters within a couple of hundred
miles, but it does get old and we didn't use the boat as much as we did
after we settled in a good cruising ground and moored.

Rough rule of thumb I've observed of actual boaters. About an hour away
is reasonable for a day trip; about 2 hours for a weekend. Yes, you can
travel longer, but people just don't do it very often.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

A question about boat weight and displacement
 

In article LKDGRCFC38078.9701851852@anonymous,
Ante Topic Mimara ] wrote:

Jere Lull writes:

Ante Topic Mimara wrote:

I am having trouble attempting to determine the weight of
a boat, with limited information about it. snip
Displacement: 6,075 lbs
Draft: 2'-2"

Is it possible to determine how much this vessel weighs from
this sort of information?

As it happens, we're about 1000# heavier and about the same size,
though taller. A couple of Xan's sisters are hauled on trailers,
but not often. Pretty much one round trip a year.

What kind of motor boat do you have?

She's a sailboat (see her page below). Her displacement -- and weight --
is nearly 1000# higher than what you have listed. As I said before, she
can be towed, but it requires a big truck.

Add a trailer and gear you're in the 7-8000# range, possibly
higher.

Yes, I can see that adding a trailer will add some weight. I
was just hoping to get some idea of how much, in addition to
determining the weight of the boat as well.

If the 6075# you quoted is correct, I'd say you'd be safe if you chose
8000# for a working number. Planning for 10,000 would possibly be safer,
but I am pretty sure everything would add up to less than that.

What is a "cradle" as it applies to boat trailers?

It's a custom frame to hold the boat safely while it's on land.
Sometimes a boat will have one, but if you haven't heard the term,
you'll probably have to get/buy/build a trailer.

As I recall, I was told a 150 with a tow package can handle
it in a pinch, but a 250 is better.

I'm totally lost here. To what kind of vehicles do you refer?

Sorry. They're the largest pickup trucks, built for heavy use. Take a
look at trucks rated to tow -- and stop -- 8-10,000 pounds.

All of the boats I have seen people back into the lakes and river
around here, just back up, and the boat floats off the trailer.
Is there another way of doing it that I do not know about?

There are other ways, but if the boat actually draws only 2'2", you
probably will be able to float off as they do, so there's no need to get
into that.

I just want to find out if it is feasible to be able to move this
boat between the river and the lakes around here, or take it to
the coast on a trailer (150 miles) so that I can go up and down
the coast, without following the river to the coast (220 miles)
on a trailer.

Ahhh! Intended use comes out!

It's feasible, most likely, but those are fairly long distances. I towed
for a decade and enjoyed playing on waters within a couple of hundred
miles, but it does get old and we didn't use the boat as much as we did
after we settled in a good cruising ground and moored.

Rough rule of thumb I've observed of actual boaters. About an hour away
is reasonable for a day trip; about 2 hours for a weekend. Yes, you can
travel longer, but people just don't do it very often.

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

A question about boat weight and displacement
 

This won't answer all of your questions.

A cradle is what a boat sits in or on on land. Some trailers are just really
flat beds with a cradle on them. Other trailers are more custom-built for a
particular boat or type of boat. A boat can be floated off some trailers at
ramps, or lifted with a crane onto or off a trailer. My yacht club has a
crane, for example, and you can drive your trailer underneath it and plop in
the water. (For launch and haulout, when a bigger reach is needed, we hire a
bi-i-ig crane.)

Some boats don't sit in a cradle, but on "stands." Depends on the boat and
other variables.

It occurs to me that one very simple answer to your dilemma would be to
visit a commercial marina and see what they suggest. This is what they do
for a living!

====

Charles T. Low
- remove "UN"
www.boatdocking.com/BDPhoto.html - Photo Contest
www.boatdocking.com
www.ctlow.ca/Trojan26 - my boat

====

"Ante Topic Mimara" ] wrote in message
news:LKDGRCFC38078.9701851852@anonymous...

Yes, I can see that adding a trailer will add some weight. I
was just hoping to get some idea of how much, in addition to
determining the weight of the boat as well.

I do not know if a trailer is available, so I assume not. I
believe I will have to have one made, if I can find out what
the weight of the vessel is.

[If you have a cradle, it can be secured to a flat bed, BTW.]

What is a "cradle" as it applies to boat trailers? I have never
seen any other kind of boat trailer that the boat does anything
but sit on top of the trailer. Is this something I must add, for
safety or travel?

....
All of the boats I have seen people back into the lakes and river
around here, just back up, and the boat floats off the trailer.

Is there another way of doing it that I do not know about?
...
I deeply appreciate your writing all you did, but it does not mean
anything to me. I do not know about many of these things to which
you refer.

I just want to find out if it is feasible to be able to move this
boat between the river and the lakes around here, or take it to
the coast on a trailer (150 miles) so that I can go up and down
the coast, without following the river to the coast (220 miles)
on a trailer.

Thanks for all the other information though!

A question about boat weight and displacement
 

This won't answer all of your questions.

A cradle is what a boat sits in or on on land. Some trailers are just really
flat beds with a cradle on them. Other trailers are more custom-built for a
particular boat or type of boat. A boat can be floated off some trailers at
ramps, or lifted with a crane onto or off a trailer. My yacht club has a
crane, for example, and you can drive your trailer underneath it and plop in
the water. (For launch and haulout, when a bigger reach is needed, we hire a
bi-i-ig crane.)

Some boats don't sit in a cradle, but on "stands." Depends on the boat and
other variables.

It occurs to me that one very simple answer to your dilemma would be to
visit a commercial marina and see what they suggest. This is what they do
for a living!

====

Charles T. Low
- remove "UN"
www.boatdocking.com/BDPhoto.html - Photo Contest
www.boatdocking.com
www.ctlow.ca/Trojan26 - my boat

====

"Ante Topic Mimara" ] wrote in message
news:LKDGRCFC38078.9701851852@anonymous...

Yes, I can see that adding a trailer will add some weight. I
was just hoping to get some idea of how much, in addition to
determining the weight of the boat as well.

I do not know if a trailer is available, so I assume not. I
believe I will have to have one made, if I can find out what
the weight of the vessel is.

[If you have a cradle, it can be secured to a flat bed, BTW.]

What is a "cradle" as it applies to boat trailers? I have never
seen any other kind of boat trailer that the boat does anything
but sit on top of the trailer. Is this something I must add, for
safety or travel?

....
All of the boats I have seen people back into the lakes and river
around here, just back up, and the boat floats off the trailer.

Is there another way of doing it that I do not know about?
...
I deeply appreciate your writing all you did, but it does not mean
anything to me. I do not know about many of these things to which
you refer.

I just want to find out if it is feasible to be able to move this
boat between the river and the lakes around here, or take it to
the coast on a trailer (150 miles) so that I can go up and down
the coast, without following the river to the coast (220 miles)
on a trailer.

Thanks for all the other information though!