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Tim Tim is offline
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First recorded activity by BoatBanter: Nov 2006
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Default Do I need trim tabs on my 23' Marquis?


Short Wave Sportfishing wrote:
On 4 Jan 2007 19:53:30 -0800, "Tim" wrote:

Actually, I know I DON'T need them, but would they be really worth
installing on my boat.


This is an interesting question and you are likely to get a variety of
answers.

To my way to thinking, probably not given how you are planning on
boating.

However (ain't there always)...

Trim tabs to help keep the boat level on those days when you are
running with a beam wind (and you do have a lot of windage) or even if
the wind is coming off a quarter (bow or stern), it will help a lot to
keep the boat straight and level.

The problem is this. If you have a moderate V (deadrise) - say 18
degrees or higher, the boat will be prone to leaning to one side or
the other no matter now much you try to put a balanced load on the
boat. The simple act of moving from one part of the boat to another
while underway will make the boat lean a little. To give you and
example, when I had the Contender Fisharound, and being 6'3" and 250,
I could make the boat lean to one side or the other when running just
by moving around. That boat had a 9'5" beam as I remember, but 24.5
degree deadrise - it made the boat very fast and it was stable on the
run, but not so much at low speeds where just moving from one side of
the cockpit to the other while trolling could offset the balance. I
could tell you a really interesting story about trim tabs sometime.
:)

Anyway, to make the point, I can stand on the gunwale of my Ranger
which has a 8'8" beam, jump up and down holding onto the T-Top and the
boat won't move at all - flat as a pancake on a griddle. I actually
experimented with it - I took a piece of aluminum square stock and
attached it to the T-top of the Ranger - it extended six feet out from
the side of the boat. It took 125 pounds at four feet away seven feet
in the air from the side of the boat to make the Ranger tilt at all.

Of course, there is no deadrise being essentially a flat hull.

With respect to putting the boat on plane, I frankly don't believe it.
I can't prove it and would be willing to be proved wrong, but on boats
that I've run and tested with trim tabs, they essentially can have an
effect on plane angle, but I maintain their worth as a adjunct to
getting a boat on plane quicker is suspect - their true worth is in
keeping the boat level which is just as complimentary to getting the
boat on plane. Just my opinion - flame suit on.



It looks to me tht in it's past life, my little ChrisCraft 169 had trim
tabs installed on it at one time, but were removed before I owned it.

My old 27' Chris Craft Cavalier had trim tabs on it, but they were
permanent mounted plates with some sort of shock absorber mounted on
them, with no manual control. but it was direct inboard.

maybe I should take it out and see how it handles first.

I do like the comment on getting better economy, even though it's hard
for me to imagine that a couple plates dragging in the water can
improve your gph.