T&T: Stern/transom flaps

[Bob Clinkenbeard]

Next project is a swim platform.  The PO said that he originally had an 
"undermount" ladder on the now disposed of platform.  He removed the ladder 
because turbulent water rises at the transom as it exits the bottom of the 
boat at cruising speed.

I have an undermount ladder I want to use on my new swim  platform...yet to 
be built.

 I have read a lot on the net about turbulence at the transom and now I am 
considering flaps/flap.
There is little information available except about large ships and trim 
tabs.  Evidently the turbulence causes some ill effects and if cured can 
increase the proficiency of fuel burn and speed increase can be realized. 
In my case, I think these would be minor.

Trim tabs for planing boats are narrow and don't really extend the hull at 
the point I need extended.
What I think would work is a SS flap even with the bottom, and parallel to 
the bottom plane.  I'm thinking 10"-12" or so and most of the width of the 
transom.  The transom is flat and has only a V rise of 1" to either side.
The rudder is about an inch short of the back of the boat and is 17" tall X 
13".  The prop is 17".
I think prop turbulence is causing the effect.

Any hydrologists on the list?  I need ideas and comments before I sink the 
boat.

Bob Clinkenbeard
24' custom trailer trawler
http://home.bellsouth.net/p/PWP-aboardbobbinalong