Positioning Trim Tabs

[Ring Owner]

Gents,

Can anyone help me out on this one. Just bought myself a Bennetts trim tab kit and after recommendations received during one of my older threads, have done away with the original "folded" tabs and am currently in the process of having a hinged set of plates fabricated.
My question refers to the actual positioning of the tabs on the transom when I get round to fitting them. According to the instructions received with the kit, the tabs should follow the "v-shape" of the hull. Minimum of 3inches from the edge and 8inches from the centre line of the engine.
However, looking through the photos on boatmad and other sites I see that some of the boats have the tabs mounted horizontally on the transom, persumably on or just under that "natural" waterline.
What is the "preferred" position for these tabs and is there a particular reason for this?
As you can see from my profile, the hull is an 18ft Ring so available space is not great.
Thanks in advance

[RossM]

do a search, i asked the same question a while back.

[gar163y]

Overall, the tabs will probably be more effective if they follow the line of the hull as per the instructions. Having said that, if your boat has a tendency to chine walk the tabs are better set horizontal to cure this. Two other points are that you will only need the left one most of the time and if set at an angle you will spill loads of coffee and beer!

[Toffy]

There's a lot to tell about trim tab positioning.
Did a search myself. Here you go :

http://boatmad.com/forum/showthread.php?t=3400 (thread from Puppiesballs/The MutzNuts : “Trim tab positioning”)
http://boatmad.com/forum/showthread.php?t=2278 (thread from Dan “Trim Tab positions?”)
http://boatmad.com/forum/showthread.php?t=4129 (thread from michaelcaine “Trim tabs, why fit them”)
http://boatmad.com/forum/showthread.php?t=5849 (your initial question : “Trim tabs - info wanted”)

Hope this helps!
T.

[Ring Owner]

Thanks Gents,

Again, your time and effort are appreciated. Will go away and do some bedtime reading then.

Hoping to have the new tabs delivered in a couple of weeks then I can see how they "look" against the hull. Either way, it is just another job that needs to be completed before next season - along with the re-wiring of the whole boat and repair to the jacking plate. Does the job list ever end!!!!

[Burty]

Depends really, mounting horizontal are less effective so in theory you will need bigger tabs to do the job but mounting at an angle tend to steer the boat if you only put one down.