What are the major DO'S & DON'TS...

[Eliminator]

...about driving tunnel hulls? Particularly, small tunnels of 21-22 feet in length with an outboard ?
Thanks
[This message has been edited by Eliminator (edited June 23, 2001).]

[dyounge]

DO: Get some seat time before trying to drive it fast.
Know that the lighter you are, the faster you go...ie full tanks, number of people etc.
Know that the boat does not turn on a dime at speed. It is point and shoot.
Pay close attention to wind and water conditions. High speed+ high wind+ rollers can kill you.
Always wear a life jacket.
Make a face like :P when you blow by other boats.
Dont: Drive the boat beyond your abilities.
Overtrim the boat.
Suddenly chop the throttle if it gets loose or you run out of balls.
I am sure that others may have more pearls of wisdom than I however, a little common sense will take you a long way. ENJOY!

[froggystyle]

Depending on your total speed, I learned not to do anything fast other than drive. At over 100, a quick diverting of the jet can pitch you over combined with a nice convenient wake and a gust of wind. Remember, the boat is trying to get airborne, so more wind is the same as more wind speed under the hull. I guess I assumed you had a jet, but maybe not. Like dyounge said, letting off the throttle when you are getting after it can pitch you out the front when the pump loads up. Bad deal. Be just as thoughtful backing off as you did mashing it.
Have fun with your boat.

[MrHavasuCat]

Not to mention the possibility of stuffing the boat if you get out of it to quick it the wrong conditions.

[Eliminator]

What do you mean by "overtrimming" ???

[rivercrazy]

If you trim the drive up too far at high speed you could cause the nose of the boat to blow over. Not a good thing!

[froggystyle]

Yeah, not only not good, but decidedly bad. A jet with a ton of power and a good tunnel is barely wet at top speed. Without a front wing, you are at the mercy of the wind totally trimmed perfectly. If you take your new hydraulic place diverter and give it a quick push at 110 just to see what happens, you will be sitting in emergency trying to figure out how you just lost control of that situation. A couple degrees makes a big difference, and I don't even know any racers that touch their diverters past 60 or so. You usually divert it down for your holeshot, and quickly move up to your maximum diversion (pre-set if you are really racing) and ride it out. Tweeking it at over a buck gets dangerous quickly.

[MrHavasuCat]

If you are going to be running an aoutdrive or outboards I would recomend a bluewater trim indicator, that way you know exactly where you are at. On my boat I know once I get past "5" on the indicator it will get a little loose, , but if you can air the boat out just on the edge you can get some good performance.

[rivercrazy]

On a jet you can get a trim gauge. I wouldn't be looking at it at high speeds though. Set it properly before going too fast..

[Austinboat]

Thanks for the tips. Ya'll are talking about "small" tunnels, what about really "SMALL" tunnels like the Formula style SST/120 racing types? Any experience with those? It's easy to assume it's shorter,(about 16 FT) over powered and on the edge of being more a plane than boat so how is it possible these boats hit 130mph? Not only that but in races with not so perfect conditions? I ask because I have found one for sale here and would like some one else's oppinion. The seller explains how the stability is hard to compare to typical V's and even some tunnels. I know the experiences of driving a boat past its designed speed but I am having a hard time understanding the physics of these boats. I guess I'm asking, what makes these boats and other racing rigs any different than pleasure boat tunnels? Is there any difference to mention?
Thanks

[Merlin]

Try www.aeromarineresearch.com. (http://www.aeromarineresearch.com.) You might find the answers you are looking for there.

[kc***boat]

Get to know the boat.