stv hull design question

[stvhelm]

I read the posts below about the stv hulls and got a little confused along the way. I'm intersted in more info on the 2 types of inverted center pod hulls offered on the euro. which of the 2 is faster? which one slows down better (safer)? which one handles better at speed? which one is most prefered for all around use? thanks

[stvhelm]

There are two current hull designs being built and marketed by our company TRIAD POWERBOATS. These are the original Roarke Summerford designs and molds. The first one was built in early 1989, is now commonly refered to as the "ski bottom". This was the first Roarke Summerford "inverted V" design. The inverted V center pod is very pronounced, runs all the way to the nose of the boat and turns up very abruptly at the nose. The strakes on the sides of the center pad are angled downward on their ouside edge. This bottom, according to Rusty Campbell,(who is a friend of mine and I see often)is capable of approximately 2 mph more speed on top end than the "MOD VP" bottom. The SKI bottom also will carry weight better because it has more lift designed into it.
Remember that Roarke was designing these hulls with one purpose in mind -- to win MOD VP races. The "SKI" bottom was quite capable of doing this, but it was difficult to "race turn" -- that is drop the boat,turn it, set it quickly, and get back in the throttle, go through the turn and back into the straightaway. This first inverted V center pod had a little to much lift to "raceturn" quickly. It "coasted" when you let off, (lift held it up too long), and the nose had too much surface planeing area, so it wouldn't sink quick enough to set the boat, sometimes the nose would want to "skip out" making it difficult to turn quickly.

The next generation bottom was built in 1990, and is a modified version of the first SKI Bottom. A brand new hull mold was made for this boat. Roarke removed a lot of the nose surface planeing area. When you look under the nose of a "MOD VP" hull, the inverted V is much less pronounced, its shallower and blends into the nose of the boat in a much smoother transition. Roarke also put a small turning edge on the starboard side of the front of the center pod to help the nose track better in the turn. (boat turns better to left than right because of this change). He also removed some of the overall lift from the boat by removing a portion of the turn downed lifting strake next to the center pad.
Only a few boats were made like this. The next generation (or evolution) of the hull was what people refer to now as the " MOD VP Hull" . A new mold was not made, but these changes were made in the existing mold. This was done in 1990 or 1991, the only change was that the last 4 or 5 feet of the two lifting strakes next to the centerpad were flattened to 0 degrees.This also assisted the boat's turning capability in a RACE situation. The current "MOD VP" hull we now manufacture is this version. As far as which is better? -- you decide --"SKI" carrys weight better, has a capable 2 mph top speed advantage, turns good (except in all out race situations). HOWEVER -- the "MOD VP" does drive a little "sweeter" ,slows down quicker when you let off, turns good to the right, turns exceptional to the left. Rusty (and others who have owned both) say that the "MOD VP" hull does drive a little nicer "set and feel" (especially on a light weight boat). Most people who order the boat !
from us specify the MOD VP hull-- probably because Rusty Campbell won so many races and so many World Championship titles with that hull....and because it is called the race hull...but we do have some people specify the "SKI" hull when they order also. Usually if they dont specify either, we build them the MOD VP hull.
Hope this information was helpful.

[David]

Was/is there an STV 'drag' bottom?
If so, how does it compare to the others?

[AnthonySS]

THANKS for sharing that with us HELMUT!

Sincerely,

AnthonySS

[Firestarter]

Yes their was/is a drag bottom. Wally does not have that mold, It was sold to Dave McPherson, along with the ProComp deck. It is in no other words a DANGEROUS design end of story.
As far as hull designs, all that was stated is exactly what I have know to be true (I learnt from Roark himself, and from Ted Greguc.)I have owned both bottoms and am prefrential to the Mod-vp. It drives easier for sure, and I also find it a little easier to get in the sweet spot, with respect to setup. I too understand that the ski bottom is supposed to be faster, but have never seen that. ( actually the real fast ones were all mod-vp bottoms ).

As far as safety----this is a key issue, you cannot chop the throttle in an STV when comming down from stratospheric speeds (over 115mph), This boat was designed with sharp sponsons that are supposed to dig (for turning) that can cause darting upon rentry.
As for everyday use, I like the Mod-vp bottom.

My 2 cents

RT