Rich's post got me to looking - just for my own edification.

This is from the Nauticus web site about Smart Tabs:

****

"SPEED REGULATION
SMART TABS start in a downward angel to maximize lift at slow
speeds. As the boat accelerates, the water pushes up on the trim
plates providing lift to the stern which minimizes bow rise, and
allows the boat to plane quickly.

Once the water pressure exceeds the actuator load rating (maximum
lift) the trim plates move up to a horizontal position eliminating any
drag."

****

Besides the fact that angels are not relevant to this discussion
except for praying for good weather, doesn't this seem counter to
accepted theory on bow lift?

Bow lift is what you need to get up on plane as I understand it. It
would seem to me that lifting the stern is exactly what you don't want
to do - you want to keep the stern as neutral as possible acting as a
pivot point - or am I wrong?

On the opposite end of this planing deal, I'm not sure how this allows
you to stay on plane longer. Even if you set the actuators to a heavy
setting, that kind of defeats the purpose - yes/no?

Later,

Tom - who is not looking to start an argument, just being curious.

Tom, to answer your first question...my two boats are a
1. a narrow, tunnel-hull, high bowed, 16 ft. flats boat known as an El
Pescador http://www.elpescadorboats.com/
& 2. a 16 ft. Carolina Skiff STD, flat bottomed, skiff style
www.carolinaskiff.com
These two boats are as different as night and day in hull configurations.

With regard to "theory on bow lift"....I'm no engineer...(a big
understatement)... but all tabs that I am familiar with... Lenco (
electric) Bennet (hydraulic) and SmartTabs (pneumatic) ....all work on the
same principle and produce similar, (though differing in degree and amount
of control), results. It is my simple impression that TABS ( any tabs)
effectively make the boat "longer" by extending the stern hull surface
outwards.

Most planing style boats have the "bow rise" built-in. Just start any
planing-hulled boat forward and the bow will rise and stay up, far too long,
until the boat gradually comes back down to "plane". I've owned over twenty
boats so far, and never had any of them that would instantly go to "plane"
without the ....Up first, level later... process. The use of trim tabs
counters this excessive bow rise and brings the boat into plane quicker. Any
planing-style hulled boat, moving on plane, is using less fuel than it would
while plowing through the waves.

It may well be that if you had a non-planing ( displacement style) hull,
that the UP/LEVEL movement was minimized. My displacement hulled sailboats
did NOT have any UP/LEVEL style startup problem, but I believe that the
questioner was speaking about a planing hull.

On the other end, when the boat is slowing down...it settles at the heaviest
stern-end much too quickly, bringing it back into an in-efficient bow-up
position. Tabs ( any tabs ) help to stop the stern from sinking quite as
fast, allowing for a longer planing time at a lower speed. I'd believe that
this attribute is caused by the "longer hull" extension effect of any tab
system.

I'm certain I can find chapter & verse on Tab's efficiency and usage in
Bennett's and other websites. The engineering studies have been done long
ago, and many thousand, perhaps millions, of boats have used tabs for well
over 30 years. If you'd like more data, I can Google it for you.

I was a skeptic about the effectiveness of tabs, too. Now that I am a user
though, I wouldn't boat without them.
regards,
--
RichG manager, Carolina Skiff Owners Group on MSN
http://groups.msn.com/CarolinaSkiffOwners
..

"Short Wave Sportfishing" wrote in message
...
Rich's post got me to looking - just for my own edification.

This is from the Nauticus web site about Smart Tabs:

****

"SPEED REGULATION
SMART TABS start in a downward angel to maximize lift at slow
speeds. As the boat accelerates, the water pushes up on the trim
plates providing lift to the stern which minimizes bow rise, and
allows the boat to plane quickly.

Once the water pressure exceeds the actuator load rating (maximum
lift) the trim plates move up to a horizontal position eliminating any
drag."

****

Besides the fact that angels are not relevant to this discussion
except for praying for good weather, doesn't this seem counter to
accepted theory on bow lift?

Bow lift is what you need to get up on plane as I understand it. It
would seem to me that lifting the stern is exactly what you don't want
to do - you want to keep the stern as neutral as possible acting as a
pivot point - or am I wrong?

On the opposite end of this planing deal, I'm not sure how this allows
you to stay on plane longer. Even if you set the actuators to a heavy
setting, that kind of defeats the purpose - yes/no?

Later,

Tom - who is not looking to start an argument, just being curious.

On Mon, 20 Dec 2004 22:36:22 GMT, "RichG"
wrote:

Tom, to answer your first question...my two boats are a
1. a narrow, tunnel-hull, high bowed, 16 ft. flats boat known as an El
Pescador http://www.elpescadorboats.com/
& 2. a 16 ft. Carolina Skiff STD, flat bottomed, skiff style
www.carolinaskiff.com
These two boats are as different as night and day in hull configurations.

I have a 20 foot Ranger CC and a 32 foot Contender (ok, it's say 31,
but it's really a 32). There is no practical deadrise on the Ranger
and a whole bunch on the Contender. :)

With regard to "theory on bow lift"....I'm no engineer...(a big
understatement)... but all tabs that I am familiar with... Lenco (
electric) Bennet (hydraulic) and SmartTabs (pneumatic) ....all work on the
same principle and produce similar, (though differing in degree and amount
of control), results. It is my simple impression that TABS ( any tabs)
effectively make the boat "longer" by extending the stern hull surface
outwards.

Most planing style boats have the "bow rise" built-in. Just start any
planing-hulled boat forward and the bow will rise and stay up, far too long,
until the boat gradually comes back down to "plane". I've owned over twenty
boats so far, and never had any of them that would instantly go to "plane"
without the ....Up first, level later... process. The use of trim tabs
counters this excessive bow rise and brings the boat into plane quicker. Any
planing-style hulled boat, moving on plane, is using less fuel than it would
while plowing through the waves.

I agree, but on the Ranger, I have no bow lift at all - it literally
goes from "plow" to "plane" at around 15 mph - you can't control it -
it just does it. But the bow has zero lift - just goes from one
attitude to the other with no transition. I've demonstrated this to
some people who don't believe and they just walk away shaking their
heads - it kind of contravenes conventional theory. :)

On the Contender, I pretty much use the trim tabs for lateral
stability and use the engine trim to keep the bow angle where I want
it on take off. I keep the trim tabs at neutral until we're rolling
along, the adjust as necessary for sea conditions.

~~ snippage ~~

I was a skeptic about the effectiveness of tabs, too. Now that I am a user
though, I wouldn't boat without them.

Understood - nothing like a little practical experience to help
clarify things.

It's just that I've noticed on my Contender, that the tab effect isn't
quite as advertised and in fact, if it weren't for the lateral bit, I
wouldn't even consider them.

I can see, though, how they would help your boat's situation. Now
that I think about it, I don't know how big Mike's boat is so maybe I
shouldn't have shot my mouth off. :)

Later,

Tom

Well, if your Ranger CC boat goes from dead still to planing it is a great
boat for you. It must be balanced out just right and everything inside must
be positioned at the right spot. I can't comment, other than to echo your
other observers and viewers... that.... I, too, am shaking my head. Happy
for you.

Your larger boat might benefit from more tab pressure, but I'll leave that
for the engineers and people at the various Tab companies. If you've got
Bennett tabs, a guy by the group-name of Tabman hangs out on
www.TheHullTruth.com and would venture an opinion I'm sure. He is the rep
for the company and has done a lot of good for users of his brand on that
site.

With regard to the original poster ..he stated that the boat tops out,
weight-wise, at 2,000 lbs. including engine and, I expect, gear. That makes
it a lot smaller than your 31/32 and maybe smaller than your Ranger. I found
a picture of that brand at
http://www.boatsville.com/used_boats...FishingBo ats

Of course, the boat that I found on the web may not be anything near what
Tom's boat looks like...but the hull shape would lead me to believe it would
benefit from tabs, a lot more than changing out props.

I was a skeptic...I am no more....Tabs work when they are
needed...............
--
RichG manager, Carolina Skiff Owners Group on MSN
http://groups.msn.com/CarolinaSkiffOwners
..

"Short Wave Sportfishing" wrote in message
news
On Mon, 20 Dec 2004 22:36:22 GMT, "RichG"
wrote:

Tom, to answer your first question...my two boats are a
1. a narrow, tunnel-hull, high bowed, 16 ft. flats boat known as an El
Pescador http://www.elpescadorboats.com/
& 2. a 16 ft. Carolina Skiff STD, flat bottomed, skiff style
www.carolinaskiff.com
These two boats are as different as night and day in hull configurations.

I have a 20 foot Ranger CC and a 32 foot Contender (ok, it's say 31,
but it's really a 32). There is no practical deadrise on the Ranger
and a whole bunch on the Contender. :)

With regard to "theory on bow lift"....I'm no engineer...(a big
understatement)... but all tabs that I am familiar with... Lenco (
electric) Bennet (hydraulic) and SmartTabs (pneumatic) ....all work on
the
same principle and produce similar, (though differing in degree and
amount
of control), results. It is my simple impression that TABS ( any tabs)
effectively make the boat "longer" by extending the stern hull surface
outwards.

Most planing style boats have the "bow rise" built-in. Just start any
planing-hulled boat forward and the bow will rise and stay up, far too
long,
until the boat gradually comes back down to "plane". I've owned over
twenty
boats so far, and never had any of them that would instantly go to
"plane"
without the ....Up first, level later... process. The use of trim tabs
counters this excessive bow rise and brings the boat into plane quicker.
Any
planing-style hulled boat, moving on plane, is using less fuel than it
would
while plowing through the waves.

I agree, but on the Ranger, I have no bow lift at all - it literally
goes from "plow" to "plane" at around 15 mph - you can't control it -
it just does it. But the bow has zero lift - just goes from one
attitude to the other with no transition. I've demonstrated this to
some people who don't believe and they just walk away shaking their
heads - it kind of contravenes conventional theory. :)

On the Contender, I pretty much use the trim tabs for lateral
stability and use the engine trim to keep the bow angle where I want
it on take off. I keep the trim tabs at neutral until we're rolling
along, the adjust as necessary for sea conditions.

~~ snippage ~~

I was a skeptic about the effectiveness of tabs, too. Now that I am a
user
though, I wouldn't boat without them.

Understood - nothing like a little practical experience to help
clarify things.

It's just that I've noticed on my Contender, that the tab effect isn't
quite as advertised and in fact, if it weren't for the lateral bit, I
wouldn't even consider them.

I can see, though, how they would help your boat's situation. Now
that I think about it, I don't know how big Mike's boat is so maybe I
shouldn't have shot my mouth off. :)

Later,

Tom

In article ,
says...
I don't know how big Mike's boat is so maybe I
shouldn't have shot my mouth off. :)




It's a "85" 21' seaway with a 1.6 OMC Seadrive on it.

I'm following, well, at least reading, both threads with interest.

I have my own thoughts on planing and it fits nicely with your
experiences with your boats Tom. I'm not hydraulics engineer but I do a
bit about them.

If I may.

Water, hell, just about any liquid, is pretty much not compressible. As
a V hull passes through it it cuts and displaces the water until it
reaches a speed where it is pushing it aside fast enough to starts to
try to compress it.

At that point the water starts to push/squeeze the bow up until it hits
the "flat" at the rear of the hull. At that point you have pretty much
become a flat rock skipping over the surface of the water with the wide
flat area of the hull trying to compress the uncompressed so it can
wallow down into it.

That being the case hull design can lead to an infinite variety of way's
a boat can come up on plane. Steep bow rise, no bow rise, etc.......

Now NOBY's post in the "what gain" thread is leaving me a tad fuzzy but
with the above solidifying in my mind I am starting to get a glimmer of
where he is going with it. I just can't, yet, quite connect all the
dots.

Again, my thanks too all respondents.

PS, They are inexpensive enough that I think I will do some
experimenting with some form of the whale tail stabilizers in the
spring. I'll let you all know how I make out with them. Right now the
TIGER SHARK VG's are the ones that have my main interest.


Mike

--
MikeG
Heirloom Woods
www.heirloom-woods.net

Well, if your Ranger CC boat goes from dead still to planing it is a great
boat for you.


A boat that does from dead still to planing....that IS something

Just to show you my heart is in the right place...if you want, you can buy
either of my used hydrofoils ( that were removed when I put on the Smart
Tabs ) for $10.00 plus shipping costs. One is from Bob's Machine Shop and
fitted my 50 hp 2 cycle Yamaha and the other is a "The Angler-Pro Series"
that fit my 40 hp Yamaha 2 cycle.

That said...I wouldn't buy them for that price...but anyone who wants them
can have them for the same price.
--
RichG manager, Carolina Skiff Owners Group on MSN
http://groups.msn.com/CarolinaSkiffOwners
..

"MikeG" wrote in message
ews.com...
In article ,
says...
I don't know how big Mike's boat is so maybe I
shouldn't have shot my mouth off. :)




It's a "85" 21' seaway with a 1.6 OMC Seadrive on it.

I'm following, well, at least reading, both threads with interest.

I have my own thoughts on planing and it fits nicely with your
experiences with your boats Tom. I'm not hydraulics engineer but I do a
bit about them.

If I may.

Water, hell, just about any liquid, is pretty much not compressible. As
a V hull passes through it it cuts and displaces the water until it
reaches a speed where it is pushing it aside fast enough to starts to
try to compress it.

At that point the water starts to push/squeeze the bow up until it hits
the "flat" at the rear of the hull. At that point you have pretty much
become a flat rock skipping over the surface of the water with the wide
flat area of the hull trying to compress the uncompressed so it can
wallow down into it.

That being the case hull design can lead to an infinite variety of way's
a boat can come up on plane. Steep bow rise, no bow rise, etc.......

Now NOBY's post in the "what gain" thread is leaving me a tad fuzzy but
with the above solidifying in my mind I am starting to get a glimmer of
where he is going with it. I just can't, yet, quite connect all the
dots.

Again, my thanks too all respondents.

PS, They are inexpensive enough that I think I will do some
experimenting with some form of the whale tail stabilizers in the
spring. I'll let you all know how I make out with them. Right now the
TIGER SHARK VG's are the ones that have my main interest.


Mike

--
MikeG
Heirloom Woods
www.heirloom-woods.net

Not having seen smart tabs anywhere before I looked them up on the web.
Sounds interesting but from the renditions they have of the units
showing how they work I have to wonder how much drag they would be
causing at trolling speeds since there isn't enough pressure to raise
them.



--
MikeG
Heirloom Woods
www.heirloom-woods.net

On Tue, 21 Dec 2004 19:15:54 -0500, MikeG
wrote:

Not having seen smart tabs anywhere before I looked them up on the web.
Sounds interesting but from the renditions they have of the units
showing how they work I have to wonder how much drag they would be
causing at trolling speeds since there isn't enough pressure to raise
them.

I had much the same thought.

Later,

Tom

I'm not a troller, so my answer is without a lot of knowledge...however, it
seems to me that many trollers put "trolling plates" on their motors to SLOW
the boat down. The few times that I have trolled ( Alaska, etc.) we were
running at 2 or 3 mph. Seems to me, that the drag created by ANY tab system
would be beneficial?????
--
RichG manager, Carolina Skiff Owners Group on MSN
http://groups.msn.com/CarolinaSkiffOwners
..

"MikeG" wrote in message
ews.com...
Not having seen smart tabs anywhere before I looked them up on the web.
Sounds interesting but from the renditions they have of the units
showing how they work I have to wonder how much drag they would be
causing at trolling speeds since there isn't enough pressure to raise
them.



--
MikeG
Heirloom Woods
www.heirloom-woods.net