Trim tabs - which ones?

RichardM

Recruit
Joined
Feb 3, 2010
Messages
3
Hi, I'm a new boy on here, I normally frequent SCUBA diving forums, so be gentle with me eh?

I'm currently running a 14ft inflatable (not a RHIB) with a 30HP short-shaft Yamaha 2-stroke. Loading with myself and up to 2 other fully kitted divers (ie 6 tanks, 3 weightbelts etc) varies between 240 and 360Kgs or between 1/4 and 1/3 of a ton.

In smooth waters, this is fine, however when running into a bit of a chop and relatively small waves/swell, it's almost impossible to get her up on the plane, which makes for some very tedious journeys and uses lots of fuel - always seems to be the return trip too, at the end of the day when we are feeling tired and emotional. It's obviously borderline because with two divers and their gear, she goes like a rat up a drain.

At first I thought about fitting hydrofoils on the motor, similar to what I had on my old Aluminium Quintrex (Australian make) but with the weight I'm carrying for diving, I'm concerned that this will put too much strain on the top of the transom and the outboard mountings, so I reckon trim tabs would be a better idea.

I'm looking at Smart Tabs or these fellers from Allinflatables.com. I am attracted to the Smart Tabs for the fact that they are self-adjusting and I like the look of the Allinflatables version because they look simpler with less to go wrong and they'd appear to have some flexibility built into them too, being PVC; it's a hard choice. :confused:

So which would be a better bet for me or is there something else, even better that I'm not yet aware of?

Richard
 
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Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Re: Trim tabs - which ones?

Nauticus is the most reputed and most used trim tabs, are shorter than second option.

Happy Boating
 

Howard Sterndrive

Rear Admiral
Joined
Nov 5, 2008
Messages
4,603
Re: Trim tabs - which ones?

A lower pitch prop is all I would try. beyond that, I think you are wasting your time and money with foils and tabs. With that load you need more power. Is the boat rated for a 40?
 

RichardM

Recruit
Joined
Feb 3, 2010
Messages
3
Re: Trim tabs - which ones?

A lower pitch prop is all I would try. beyond that, I think you are wasting your time and money with foils and tabs. With that load you need more power. Is the boat rated for a 40?

It is but I'd prefer to avoid shelling out another $5000 for a new motor, if it comes to that, I'll just put up with the 30. As I said, with two divers, she flies and she goes ok with 3, it's just when pushing into a short chop that I can't get her moving as well.

Whilst I can put up with this, I would like to fix it up if I can; I found the hydrofoils worked well on my last boat, so was looking at this as an alternative that puts less strain on the motor and transom.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Re: Trim tabs - which ones?

That sib/engine combination should plane well with 3 mates + gear, probably are running a under inflated sib, inflate all chambers and keel to at least 3.0 psi/0.20 bar. Buy a pressure gauge for evenly air fills between chambers.

Happy Boating
 
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