Oar Length and Boat Size
 

Now I realize this is primarily a group to discuss "cruising" and it's
rather difficult to comprehend "cruising" in a boat with oars operated
manually by a wheezing old geezer; however, my sometimes fertile mind
comes up with these scenarios and what better place to find the answer
than in rec.boats.cruising, the hangout of some of the brightest minds
in boatdom.

Prologue accolades aside, here is the problem(?).

1--I've already bought the Suzuki 2.5 hp outboard for our open utility
boat.

2--The boat is 14' 6" long with a 61" beam, 50" bottom width and
approximate 26" side depth.

3--In case the ultra-dependable Suzuki should fail or (gasp) run out
of fuel with no more present in the boat, I would have to row the $#@#$
% thing back to shore.

4--The oars I currently possess are 7' in length and they worked fine
for the dinghy we previously owned.

5--My concern now is that they may be too short with the wider beam
and higher side depth for my monkey arms to maintain a grip on them
while they dip sufficently into the drink and propel us forward.

Is there a guide anywhere that would determine proper oar size (i.e.
length) for an open rowboat that would take into account the
measurements of said rowboat?

-Jay
(trying to cover all bases before heading to the open sea...# : ^ )

Oar Length and Boat Size
 

On Mon, 28 Apr 2008 13:12:47 -0700 (PDT), Jay
wrote:


2--The boat is 14' 6" long with a 61" beam, 50" bottom width and
approximate 26" side depth.

3--In case the ultra-dependable Suzuki should fail or (gasp) run out
of fuel with no more present in the boat, I would have to row the $#@#$
% thing back to shore.

4--The oars I currently possess are 7' in length and they worked fine
for the dinghy we previously owned.

5--My concern now is that they may be too short with the wider beam
and higher side depth for my monkey arms to maintain a grip on them
while they dip sufficently into the drink and propel us forward.

Is there a guide anywhere that would determine proper oar size (i.e.
length) for an open rowboat that would take into account the
measurements of said rowboat?

-Jay
(trying to cover all bases before heading to the open sea...# : ^ )

You could make an accurate drawing of the cross section of your boat.
You then draw in an oar that looks right, and measure the drawing.

Casady

Oar Length and Boat Size
 

"Jay" wrote in message
...
Now I realize this is primarily a group to discuss "cruising" and it's
rather difficult to comprehend "cruising" in a boat with oars operated
manually by a wheezing old geezer; however, my sometimes fertile mind
comes up with these scenarios and what better place to find the answer
than in rec.boats.cruising, the hangout of some of the brightest minds
in boatdom.

Prologue accolades aside, here is the problem(?).

1--I've already bought the Suzuki 2.5 hp outboard for our open utility
boat.

2--The boat is 14' 6" long with a 61" beam, 50" bottom width and
approximate 26" side depth.

3--In case the ultra-dependable Suzuki should fail or (gasp) run out
of fuel with no more present in the boat, I would have to row the $#@#$
% thing back to shore.

4--The oars I currently possess are 7' in length and they worked fine
for the dinghy we previously owned.

5--My concern now is that they may be too short with the wider beam
and higher side depth for my monkey arms to maintain a grip on them
while they dip sufficently into the drink and propel us forward.

Is there a guide anywhere that would determine proper oar size (i.e.
length) for an open rowboat that would take into account the
measurements of said rowboat?

-Jay
(trying to cover all bases before heading to the open sea...# : ^ )

try... scroll down to 'oar length' in each case...........
http://www.eartheasy.com/rowpage.htm
http://www.unclejohns.com/skiff/faq/default.htm
http://www.shawandtenney.com/wooden-rowing-oars.htm

Oar Length and Boat Size
 

Shaw & Tenny has a formula for the proper length for a pulling oar.

Inboard length should be 1/2 the beam between oarlocks + 2"
Total length should be 1/7 the inboard length times 25.

Assuming your oarlocks are aft of the maximum beam (and make the calculation
easier) call the distance between oarlocks as 52". Inboard length would be
26+2 or 28" . 1/7 of 28 is 4" times 25 is 100" = 8' to 8'6" in standard
lengths. For your maximum beam 9' would probably be better but measure the
oarlock beam first.. That will put the pull just above waist level. Much
shorter and the slope gets to steep. You will be pulling up at shoulder
level which in inefficient and uncomfortable. Any longer and it takes to
much movement to clear the water on the back stroke.

At $250/pair a set of 8' spruce Shaw & Tenneys with a good set of leathers
might be overkill for a working dink but they are a work of art and a joy to
pull with.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Jay" wrote in message
...
Now I realize this is primarily a group to discuss "cruising" and it's
rather difficult to comprehend "cruising" in a boat with oars operated
manually by a wheezing old geezer; however, my sometimes fertile mind
comes up with these scenarios and what better place to find the answer
than in rec.boats.cruising, the hangout of some of the brightest minds
in boatdom.

Prologue accolades aside, here is the problem(?).

1--I've already bought the Suzuki 2.5 hp outboard for our open utility
boat.

2--The boat is 14' 6" long with a 61" beam, 50" bottom width and
approximate 26" side depth.

3--In case the ultra-dependable Suzuki should fail or (gasp) run out
of fuel with no more present in the boat, I would have to row the $#@#$
% thing back to shore.

4--The oars I currently possess are 7' in length and they worked fine
for the dinghy we previously owned.

5--My concern now is that they may be too short with the wider beam
and higher side depth for my monkey arms to maintain a grip on them
while they dip sufficently into the drink and propel us forward.

Is there a guide anywhere that would determine proper oar size (i.e.
length) for an open rowboat that would take into account the
measurements of said rowboat?

-Jay
(trying to cover all bases before heading to the open sea...# : ^ )

Oar Length and Boat Size
 

Jay wrote:
Is there a guide anywhere that would determine proper oar size (i.e.
length) for an open rowboat that would take into account the
measurements of said rowboat?

Put the blade end of your 7' oar against the inside transom and lay
the oar across the seats lengthways in the boat as close to each side
as you can get them. If the curve of the sides leaves too much wasted
space between the the oars and the sides, your oar is too long. Cut it
off LoL!
Seriously, for back up, 7' should be fine. I have 7' oars and I have
no trouble at all rowing my 14' OR my 16' skiff. If they feel too
short, just shove 'em outboard a little and keep on rowing.
But try your 7 footers before you buy anything longer. And think about
how you're going to store anything longer too. it. If you honestly
think 7' won't work, buy something longer but get something you can
take apart for storage. And remember, you may never use them anyway.

Rick

Oar Length and Boat Size
 

"Jay" wrote...
1--I've already bought the Suzuki 2.5 hp outboard for our open utility
boat.

2--The boat is 14' 6" long with a 61" beam, 50" bottom width and
approximate 26" side depth.


Not wanting to argue with the Shaw & Tennys formula, but 1.5Xspread
+freeboard is a good starting point. It will be closer to a minimum
for a boat with much weight, if the the oars have even half-decent
balance.

3--In case the ultra-dependable Suzuki should fail or (gasp) run out
of fuel with no more present in the boat, I would have to row the $#@#$
% thing back to shore.

4--The oars I currently possess are 7' in length and they worked fine
for the dinghy we previously owned.

5--My concern now is that they may be too short with the wider beam
and higher side depth for my monkey arms to maintain a grip on them
while they dip sufficently into the drink and propel us forward.

Is there a guide anywhere that would determine proper oar size (i.e.
length) for an open rowboat that would take into account the
measurements of said rowboat?


Yes.
Have you tried rowing the boat with your oars & the likely load in the
boat? The usual cheesy dinghy oars are likely to break your heart
trying to make any progress rowing. IMHO the reason why so few people
take rowing seriously as a means of practical movement is that so few
have any experience with practical gear.


"Glenn Ashmore" wrote:
Shaw & Tenny has a formula for the proper length for a pulling oar.

Inboard length should be 1/2 the beam between oarlocks + 2"
Total length should be 1/7 the inboard length times 25.


And that's for "pulling boats" most likely, fairly light & low drag,
fairly low freeboard. A good guide especially if Jay is going to the
expense of getting decent oars.

An oar with an efficient blade and good balance is more complicated
than the pole with one end flattened that are usually sold as "oars."
Like all technology, it has developed considerably... the basic
simplicity of the device can be misleading... consider the difference
between different types of hammers, for example.


Assuming your oarlocks are aft of the maximum beam (and make the calculation
easier) call the distance between oarlocks as 52". Inboard length would be
26+2 or 28" . 1/7 of 28 is 4" times 25 is 100" = 8' to 8'6" in standard
lengths. For your maximum beam 9' would probably be better but measure the
oarlock beam first.. That will put the pull just above waist level. Much
shorter and the slope gets to steep. You will be pulling up at shoulder
level which in inefficient and uncomfortable. Any longer and it takes to
much movement to clear the water on the back stroke.


Agreed, but in the absence of high-priced well-balanced oars, too
short by a little is better than too long. And the beam of the boat
matters less than the spread between oarlocks, not quite the same
thing.

At $250/pair a set of 8' spruce Shaw & Tenneys with a good set of leathers
might be overkill for a working dink but they are a work of art and a joy to
pull with.


Dunno about "joy" the way most people go to great lengths to avoid
physical exertion... however, they are certainly a heck of a lot more
rewarding than the cheapos from your local discount marine outlet, or
(shudder) those stupid plastic & aluminum things they give away with
inflatable dinks.

Back in the Victorian era, there were quite a number of rowing
cruisers intended for inland waters & rivers; elegant craft with
elaborate tent enclosures and hulls that slipped thru the water
easily. Great for fishing & exploring.

Fresh Breezes- Doug King

Oar Length and Boat Size
 

wrote in message
...
On Wed, 30 Apr 2008 14:59:21 -0700 (PDT), wrote:

"Jay" wrote...
1--I've already bought the Suzuki 2.5 hp outboard for our open utility
boat.

2--The boat is 14' 6" long with a 61" beam, 50" bottom width and
approximate 26" side depth.


Not wanting to argue with the Shaw & Tennys formula, but 1.5Xspread
+freeboard is a good starting point. It will be closer to a minimum
for a boat with much weight, if the the oars have even half-decent
balance.

3--In case the ultra-dependable Suzuki should fail or (gasp) run out
of fuel with no more present in the boat, I would have to row the
$#@#$
% thing back to shore.

4--The oars I currently possess are 7' in length and they worked fine
for the dinghy we previously owned.

5--My concern now is that they may be too short with the wider beam
and higher side depth for my monkey arms to maintain a grip on them
while they dip sufficently into the drink and propel us forward.

Is there a guide anywhere that would determine proper oar size (i.e.
length) for an open rowboat that would take into account the
measurements of said rowboat?


Yes.
Have you tried rowing the boat with your oars & the likely load in the
boat? The usual cheesy dinghy oars are likely to break your heart
trying to make any progress rowing. IMHO the reason why so few people
take rowing seriously as a means of practical movement is that so few
have any experience with practical gear.


"Glenn Ashmore" wrote:
Shaw & Tenny has a formula for the proper length for a pulling oar.

Inboard length should be 1/2 the beam between oarlocks + 2"
Total length should be 1/7 the inboard length times 25.


And that's for "pulling boats" most likely, fairly light & low drag,
fairly low freeboard. A good guide especially if Jay is going to the
expense of getting decent oars.

An oar with an efficient blade and good balance is more complicated
than the pole with one end flattened that are usually sold as "oars."
Like all technology, it has developed considerably... the basic
simplicity of the device can be misleading... consider the difference
between different types of hammers, for example.


Assuming your oarlocks are aft of the maximum beam (and make the
calculation
easier) call the distance between oarlocks as 52". Inboard length would
be
26+2 or 28" . 1/7 of 28 is 4" times 25 is 100" = 8' to 8'6" in
standard
lengths. For your maximum beam 9' would probably be better but measure
the
oarlock beam first.. That will put the pull just above waist level.
Much
shorter and the slope gets to steep. You will be pulling up at shoulder
level which in inefficient and uncomfortable. Any longer and it takes
to
much movement to clear the water on the back stroke.


Agreed, but in the absence of high-priced well-balanced oars, too
short by a little is better than too long. And the beam of the boat
matters less than the spread between oarlocks, not quite the same
thing.

At $250/pair a set of 8' spruce Shaw & Tenneys with a good set of
leathers
might be overkill for a working dink but they are a work of art and a
joy to
pull with.


Dunno about "joy" the way most people go to great lengths to avoid
physical exertion... however, they are certainly a heck of a lot more
rewarding than the cheapos from your local discount marine outlet, or
(shudder) those stupid plastic & aluminum things they give away with
inflatable dinks.

Back in the Victorian era, there were quite a number of rowing
cruisers intended for inland waters & rivers; elegant craft with
elaborate tent enclosures and hulls that slipped thru the water
easily. Great for fishing & exploring.

My cousin's husband has a Dovekie. He loves it. Probably rows it more than
he
sails it.


Fresh Breezes- Doug King

I carry two sets of oars for my dinghy. One is a typical short set of
collapsable oars which I use as "backup" when I will be mostly motoring. I
also
find that they are preferable for poking around docks and such. The long
oars
can get in the way sometimes. If I'm really going rowing, I take the long
oars
instead, which really do make a huge difference in my speed and the effort
required to attain it.


If you do not have an outboard engine and only use oars to move your rigid
dinghy you need a good set.
Around here you can buy long oars and cut them to right length and shape to
suit you and your dinghy.
In my case I prefer to make my own oars. I don't save any money but it
give me more flexibility to configure the length and shape to suit the beam
of my dinghy, the oars locks, the size of my hands and the propulsion.
Normally it takes me three dry runs before completing a set. Meaning that I
first use the oars then I adjust them until I am satisfy.

Oar Length and Boat Size
 

"Jay" wrote...

Normally it takes me three dry runs before completing a set.

Besides, I find it less demanding to row in the air than in the water ;-))

--
http://francois.lonchamp.free.fr
Un doigt de linguistique ... et un soupçon de voile