Originally Posted by Easyrider
The difference is that the sibs with speed tubes still have a centeral keel/hull-this is the part that causes the slamming in a chop.The Surfcat hull is a catermaran hull with a deep but thin sponson/hijacker either side of a flat deck-the best way to see the profile is to google an image search for "thundercat boat" or "zapcat" as these have exactly the same setup(slightly different profile though).
I should imagine that it is possible to add speed tubes, which will make it more stable at speed, but you will still get the pounding when out in a slight chop due the hull profile.
Hope this makes sence.
I have been looking at the Cats for a couple of years now, but have yet to see one in person other than one I saw go past on the Main river at about 45/50MPH one day, by the time I got in the boat, he was long gone. A friend who spoke with him later told me he was a South African, here on vacation, and I never saw it again. I think I would enjoy one, but they are pricey.
I saw the Avon with the Speed Tubes last week, and to tell you the truth I really didn't consider the influence of the inflatable keel. I would think it would have a affect on the tunnel effect by reducing the lift.
Would Speed Tubes mounted on a flat bottom SIB with a aluminum, air floor, or wood floor, without the inflatable keel, achieve the same overall lifting affects as a “Ceasar surfcat”?