T2x

Some years ago the builder told me that he started with a Shadow hull on the 30 footer......... as if that was a complement to me.....and George. I think Gazelle was involved with the project as well.........and he had been at the Shadow shop having a boat built after George and I left the company....so that sort of ties in.

There were various changes made in reducing the overall size of the boat..and retooling the deck...and the result was a....... decent........ little cat.

One glance at the 36 shows it to be a stretch of the tunnel and sponsons...... overall width appears to be merely a function of deck size on the 36 without expanding the running width and surfaces significantly.

The 36 is certainly more narrow for its length than the 30...and the handling is indicative of those proportions.

T2x

P.S. "In the Loo"...... means in the head...Johnny....toilet.....get it?

Steve 1

Gazelle now there is a name from the Past.

macvtt

Any thoughts on this
At about 62mph the boat starts to porpoise and continues to do so at 71mph. Any ideas??
Thanks again

mmwalters

My 30' motion did the same thing. A tunnel tab completely eliminated the problem

jbrauer

T2x - Thanks for the straight scoop.

I hate to see anyone's hard work, $$$'s, and time stolen by splashing. On the other hand, I've really enjoyed my boat so far. Hopefully, it's a stepping stone to a 32 or 36 Skater in the future.

Maybe you can help with a set-up question: My boat has twin stock HP500 carbs, 1.36 gears, labbed 30" Bravo's and has run a best of 100 GPS @ 5,200 RPM with four people and about 80 gallons of gas, 85 degrees, about 85% humidity.

I'm sure I can get a bit more speed by removing the extra weight but more important, is the source of the porpoise starting in the high 80's. If the water is choppy it disappears.

At first I thought I needed to add weight up front to settle the bow down, but now I think it may be sticking and need help releasing from the water.

Should I try removing weight from the bow area and relocating as much toward the transom as possible?

What do ya' think?

macvtt

jbrauer: We also have a 30ft Spectre that started to porpoise at about 50mph and continued up to about 70 mph. Like mmwalters said, installation of a tunnel tab fixes the problem. It maybe the 36 cobra is doing it for a diff reason and it might be a clue to my problem.

Thanks again.

HMJudge

I have a 1999/36/cat/ t500 hp's/20hrs, on trailer price to sell CALL HARRY JUDGE 410 827 0097

T2x

Most cats will porpoise in transition from hydrodynamic to aerodynamic lift.......... and many will benefit from either a wedge in the tunnel or a tunnel tab....

However in the case of a very narrow "stretch" design...the boat will never have enough air packed in the tunnel to truly lift it...so the porpoise may not be curable.

My advice is keep the 36 footer as a 65 mph fishing platform, and don't take it too seriously as a performance cat.

T2x

macvtt

fishing... what is that??? our only problem is we wouldnt know what end of the fishing pole to hold.
I am guessing a wedge goes at the back of the tunnel and keeps more air in to give more lift..

SHARKEY-IMAGES

And you haven't run into him yet? Afterall, he now resides in Fla.