Ballast tanks, Tunnel Tabs ?
 

O.K. I have a 26foot Ocean Express it hops on flat at full bore, but I can't drive through it! I'd like to find out where I can buy a ballast tank preferably a collapsing one instead of a small fuel tank. So I can pump in weight on flat water, dump it in the rough. That or I could put an inverted Tunnel Tab to direct air instead of water (like on the big Skaters) . Anybody know who has 'em? How to modify to suit? thx. Bill :rolleyes:

Several companies make bladder style tanks for fuel and water. Check BoatUS or West Marine. The fittings on these tanks aren't real big (between 3/8" and 5/8"), so it might take a while to get water in and out. They also make bladder tanks to weigh down the back of ski boats to get big wakes for wakeboarders,
like this .
I've seen tunnel tabs made by taking a trim tab (or two) and adding a plate that spans the tunnel. (Make sure all the tab rams are hooked up to a single pump, not separate ones.)

common on lots of cats, a tunnel tab can be both fixed or hydraulic, the both work, believe it or not. a fixed one will get rid of the porpoise but you cannot adjust it (obviously) if you want to bring down the bow. It gives the illusion of being longer so the compression of air smooths out. You need to have it made just for your tunnel area in order for it to work properly. just about any good aluminum welder can make one. good luck. Craig