Any one available for the 24's ? I've seen it for the 21's though

what size is this one?

zero... your 28 trailers bunks are diff than mine...mine support the hull on the sponsons all the way out to the end of the notched transome not under the tunnel...is that a skater trailer??? mine also fits pretty tight and will get a little stuck because or the wood/carpet expansion I think...kinda sucks launching sometimes.

Not a skater trailer, aluminum one built by someone in New York , I added 2x2x.25 stiffeners on the main rails, and new 6 k axles with a brakerite system. It loads unloads very easy. The tab is a stock Mercury 180 I think. Square and about 14 x14

Kirk, sounds good, I was told that no less than 19" or otherwise it wouldn't be long enough to touch the water, But if yours work it's good news.

Thanks,

Ivan

You are not touching the water with it, you are moving the air passing through your tunnel......... If it touches the water, you're doing it wrong.....

Thanks Ryan, Totally agree, I was thinking that 15.5" x 17" should work, what do you think?

right...reducing the area the air has to escape the tunnel so it wont "burp" as easy.

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I'm trying to learn more about cat characteristics , can you please explain what the "burp" is?

are you saying that compressed air inside the tunnel exit in bursts?
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yes noli...my 28 does it 50-60mph...the air compresses and lifts the hull then releases(burps) causing a hop until you are moving fast enough to keep the air compressed/packed and keep the hull "flying". by adding a tab you can adjust the space the air has to leave the tunnel so you have some control...I've never used one...I'm still learning on my 28 but I do know leaving it down and turning is BIIIIIG no no!!!!

http://www.youtube.com/watch?v=UNdpdxrjOQ8

hop/burp at about 40sec-1:19....then again as he slows around the 3:45 mark. Love the sound of twin outboards...the 2.5's sound better but the 300xs's aren't bad either LOL.