TRIM TABS

[pissativlypossed]

I have taken the decision to have trim tabs fitted on my Jeanneau Prestige 36, the question is which ones should i buy. Volvo have introduced a new design which work by raising or lowering a blade directly into the water under the transom, as opposed to the airfoil type typically used and raised hydraulically.
They claim (and I have seen a report in MBM confirming this) that they operate much quicker, retract fully so that they are less prone to corrosion and fouling. Cost fitted will be about £1600, this is about the same as conventional tabs. What do you think?

<hr width=100% size=1>"Open Another Bottle"

 

[simongoldthorpe]

Is it obvious that you need them, and how do you think they will help?

Not making a point - just interested in why the manufacturers didn't fit them as standard if they are necessary.

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[Rob H 37]

Had problems with mine lately and these guys have responded very quickly with advice and suggestions to resolve the issues - great post sales!

Lots of stuff on the website if your interested:

trimtabs@earthlink.net
www.bennetttrimtabs.com

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[jfm]

I'd definitely get those volvo QL blade jobs

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[oldgit]

Would have thought that sticking what is in effect a plate of metal or whatever directly into the water flow must create loads of drag and not much lift,where as the aerofoil type would do the opposite.However if you have more surplus engine power than you know what to do with,mebbe a bit extra drag is not a big deal.
Ps.Was that your boat I saw down in Brighton a few weeks ago?

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[Wiggo]

why? Apart from the short review in the mag a month or three back?

<hr width=100% size=1>Hung like Einstein, and smart as a horse.

 

[pissativlypossed]

Having researched the performance of boats with and without tabs, it appears that tabs can actually increase top speed. My main reasons for fitting are to improve visibility from the lower helm when only just over the "hump", swmbo being a short arse struggles to see when the bows are up, I also fancy the idea of being able to trim the boat when heeled and everything i have read about rough weather handling recommends the ability to alter the trim to suit the prevailing conditions.
"Too Much Horsepower" ? Surely that,s not possible!
I guess the hull designers have to compromise and produce a hull that is good all round, trim tabs must alter the fluid dynamics of the hull form to better match differing speeds.
Jeanneau state that the 36 does not need trim tabs, although they are fitted as standard on the 32.
No not me, i've never been to Brighton.

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[hlb]

Yep, there good for lowering the nose, to see over.. I cant see a bloody thing from downstairs less I drop the tabs. Also helps with head seas.

<hr width=100% size=1> No one can force me to come here. I'm a volunteer!!.

Haydn

 

[Renegade_Master]

I have trim tabs on my F36 and it certainly needs them. It has a Genny which adds weight to the transom area. Also today for instance I had 7 peeps on board of which two were pretty big well fat actually, guys on the fly starboard side. Needed a hefty adjustment on the tabs to level her off. Also need them when seas and/or wind are from different directions etc

I have to say I dont know of any other manufacture of planning hulls which say the boats wont need em. Thought they would be essential bit of kit.



<hr width=100% size=1><A target="_blank" HREF=http://www.suncoastmarine.co.uk>Sun Coast Sea School & Charter</A>

 

[ArthurWood]

Not sure I want trim tabs to act very quickly; that could cause all kinds of handling probs. I'm surprised a 36 didn't come with t-tabs as std.

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[oldgit]

Re: Trim tabs.

the tabs give me a speed increase of around .5 to 1 knot,but the main difference is to lower the bow about 2 feet or so which makes big difference to forward visibilty.Is it beyond the wit of designers to produce a boat that sort of rides bow down at displacement but rides level at high speed.The amount of drag generated by a plate forced in the water flow must be enourmous,drop a tethered bucket over the side and try to hold on.Air craft use this type of tab to break up a smooth airflow and to slow down by creating lots of drag.

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[spannerman]

I have fitted many types of trim tab to various types of boats, and recently tested a Norwegian Navy Patrol Boat with the blade type tabs. THEY ARE NOT FOR THE FAINT HEARTED!
This vessel had twin VP 74's with jet drives and although weighing 11 tonnes did over 40 kts. They are used for steering at high speed as opposed to leveling the boat, when you use these tabs they are either on or off with instantaneous effect, the boat doesn't heel when turning but does the marine aquivalent of a handbrake turn slewing fthrough 90 degrees with out much loss of speed and takes a lot of anticipation to come out on the right heading.
Obviously they were set up for this particular vessel, but I feel they are not so user friendly as the regular type, which will provide a lot more lift a slower speeds and for getting on the plane plus more precise control for levelling your boat, which I assume is why you need them.

regards Steve

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