Speed tubes? will it matter?

I have a small livingston catamaran...12' long, weighs about 160lbs. I have tohatsu 25hp 2 stroke with a ballistic stainless prop...it runs pretty well, not quite as fast as I would have hoped but still respectable. I use it as a little surf exploration platform in my area...anyways, I have been into small cats for a while and really like the zapcat performace. Many probably know what I am talking about when I mention zapcat, and what I am really curious about is the speed tubes, or hi lift sponsons that they employ at speed to decrease wetted surface area. I have a notion to make some wood skinned 'speed tubes' for my little cat to see if I can realize any performance increase over what I already enjoy...it seems to run a little wet when at speed.

Anyways, any thoughts? I was thinking I might just try to mimick the tubes that are currently used on the zapcats in terms of width and with the hard edges to spray deflection...I think the zapcat tubes are about 5-6" wide back in the planing zone...the planing area on the livingston is approximately 14-16".

Brandon

 

Zapcat: http://www.zapcat-racing.com/
I'm not sure exactly what you mean by "speed tubes" in this case... are you referring to the RIB-like sponsons? Or something below the waterline? I recall a Zodiac a few years ago that used the term "speed tubes" to refer to a couple of inflatable pontoons glued to the bottom in an attempt to make an inflatable monohull act a bit like a cat....

 

I guess I am more referring to the primary planing area for the zapcat...at speed it rides on that narrow planing surface at the bottom of the tube. I was thinking that my boat is in essence one of these cats without the sponson at the bottom of tube for high/operational speed planing. I would imagine my wetted surface area is similar to an inflatable of comparable size (not RIB, sport deck or whatever they call it...really low v).