A buddy of mine has that set up on his boat don't know why but he cant trim the boat for sh't, it pulls to the side.

It seems to me that it could be a real problem trying to trim a boat with tabs and a diverter.  If not just right, wouldn't they work against each other?

Thats exactly what happens .

Trim tabs can also be installed horizontally to keep a hull from chine walking .

-beerjet-

On a lot of  boats they are an absolutle neccesity, diverter or not , some they seem to have no effect we use them  for "tuning". In the "nuetral position they make the boat think its longer and adjusted or actuated down they create a kind of "hook" (lifting) at the bottom of the stern to help force the bow down , tunnels use them to close down the air drafting thru and help with lift  The Sanger wouldn't be drivable at all without them 

Well, then, I guess I'll keep the ones that came with my new project and put them back on.  Thanks