We have been through this before. Catamarans are in the laminar flow regime. That means the water touching the hulls does not move. For all practical purposes, as long as the surface roughness is the same, it does not matter what is on the surface.
Because wax makes the surface smoother a hard wax surface, should make you a little faster. Hydracoat, hydracote, etc. are supposed to work by adding something to the water to reduce boundary layer friction. The only data I have ever seen says you need a lot (about 1 beer bottle per day) A few drops wiped on before a race is not going to do anything, for very long.
I do not know how this, "do not wax" idea got started. "Welcome To A Fleet" has helped it and some other odd ideas keep going. I do know that knowledgeable people have told annoying novices silly things like "don't wax your hull and 2000 grit wet sand it with the grooves all going in the same direction" or "wipe the rudders with raw fish oil" and armor all the tramp to help you get across faster".
If you really want your boat to go faster, wash it really good at the regatta site.
I will not argue this point anymore, go look it up for yourselves.
As for vertglass and such, I used it on a monohull I was trying to sell. I think it is thinned water based polyurethane. Think of it as a delicate decorative finish. It is sensitive to UV and do not ever use harsh cleaners. It will look like old varnish. Opps or ammonia will take it off if it starts to look bad. I have never used it on catamarans.
It is slippery but that can be fixed. I use my leftovers to make non-skid. I add Interlux grit to it and roll it where I want it.
Carl
" I likes to rub me and me boat down with day old Squid before I race"! Ow, me head hurts ...3m wax makes her slide right up on the beach and straight thru umbrella and beach chairs just ask mr. Chip from Delray. The day he slapped a tourist sunglasses off with rudder was pretty impressive too,as his 6.0 was skidding sideways sailing up the beach, the bottoms of these boats are all in great shape still.
I've been using Starbright marine polish with teflon for quite a few years. I don't know if it's a wax or not.
![[Linked Image]](http://www.palmbaymarina.com/032904parts5.jpg)
This stuff is to protect a good finish not for restoration. I put two coats on about twice a year and it seems to keep my new boats looking new. It also makes the hulls slicker so that they wash easier. I would not go near my hulls with sandpaper until they were in bad shape with lots of oxidation. I would also not ever paint a cat. The paint looks great until it starts getting dinged up then the old color shows through and the boat starts looking bad.
Mike Hill
www.stlouiscats.com
I disagree that cats are in the laminar flow regime. They may be traveling at a speed where one would expect laminar flow under ideal conditions, but there is nothing laminar about the the flow near the air-water interface. Too much entrained air and eddies from the wave action. And those eddies will be deep enough to affect a portion of the dagger and rudder, so I'd skip prepping for laminar flow on those, too. Another problem with laminar flow is that it separates more easily than turbulent flow and separation is the big drag producer.
Once you accept that laminar flow is, at best, a fantasy and, at worst, undesirable, then you can move on to the smooth vs "rough" argument. Personally, from the journal articles that I've read, I see turbulence as sort of a microscopic version of separation. With separation, there is an adverse pressure gradient that builds up near the surface due to viscosity, and when this pressure reaches a certain value, the flow separates from the surface forming a coherent eddy structure behind the object. The way to prevent this from happening is to induce randomized, turbulent flow which brings energy down closer to the surface. Well, a similar thing occurs in the boundary layer of fluid. A coherent vortex structure builds up with vortices forming and bursting in periodic fashion and the thinking is that a randomized "rough" surface prevents this coherent vortex structure from forming.
But, there's arguments both ways, some more supported by experimentation and theory than others.
Not that I'm worried about a bit of this on my cat.
So which produces the "lesser of two evils", the rough or the smooth?
Rough. Though rough is on the order of hundredths of a millimeter. Plus, there's the possibility that the same disturbances that prevent laminar flow could prevent the coherent vortex structure from forming so the point could well be moot. 
Extrapolating results from one situation to the next doesn't always work.
Good to know, although I'm going to keep my hulls shiny until someone can prove to me that the shiny hulls are slowing me down more than a blown tack or getting rolled at a starting line...
Smooth vs. Rough or Textured? Remember the 12 meter Stars & Stripes down in Australia. Riblets. They won that one. Fun topic. 
RIBLETS-You do not know what a riblet is? It is not an animal. Airlines in the United States are saving $300,000 a year because of riblets. Here is the story behind them:
Scientists at NASA tried to figure out how certain water creatures could swim so rapidly. They studied porpoises and sharks for months. The friction of the porpoise's body as it moves through the water ought to be great enough to slow it quite a bit. Yet the amount of drag that should be present-simply was not there! Given the drag of the water and the amount of flipper motion, something was enabling the porpoise to swim much faster through the water than it ought to be able to swim.
Then the experts figured it out: riblets. These are small triangular-shaped groves on the outer surface of the porpoise's skin. They are also found on fast-swimming sharks, but never on the slow ones. These grooves run from front to back. As the water touches the body, it is carried along in those riblets, and this reduces the amount of frictional drag as the large creature swims rapidly through the water.
NASA's Langley Research Center developed the riblets and tested them in wind tunnels. They then asked 3M Company to manufacture riblets in large, flat vinyl sheets. When these sheets were placed on the outside of large airplanes, the resulting savings were immense. It now costs airline companies a lot less in fuel to fly a jet liner a given distance.
Just when you think you got it all figured out. 
Kind of like the dimples in a golf ball. Should we all be orange peeling our gelcoats? Maybe next time you mess up a paint job you can tell them "Those aren't fisheyes, those are speed riblets."
-Rob V.
Nacra 5.2
Panama City
More on riblets.
http:/
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So it looks like boats sanded with 100 grit with the flow would be the fastest.
I always knew my 18 was fastest with the 100 grit finish.
Everyone can be happy all the time...
Due to flow types The ideal is a polished hull for the forward third, sanded for the rest, and a waxed stern to repel water..
Mike,
One of the articles indicated that this advantage was lost if the angle of attack (direction of water vs. direction of riblets) increased over 15%. I would guess that the bobbing up and down of the boat would cause large deviations of the AOA, which would reduce the efficiency.
Also noted was the increase in total wetted surface caused by the riblets, which if memory serves, increases drag... Do the benefits outweigh the drawbacks? You be the judge.
Interesting discussion nonetheless....
There was a paper in Nature, v388, 21 Aug 97, pp 753-755 with a summary on pp 713-714 that described a test using random protuberances. The random did better than the regularly placed roughness, presumably because the regularly placed roughness produced a coherent vortex structure, albeit smaller than the smooth surface structure. Has the added benefit of not needing to be aligned with the flow, though the test setup in the the Nature paper was flow in a channel, not past an object.
The proper way to test something like this would be to use the smooth surface area of your object as the reference area. That way, any effect of the larger gross surface area are factored into the difference in drag coefficient. However, a vendor presenting the data might disagree with what is proper.
gelcoat shmelcoat, buy a boat with a high quality paint job. Super slick yet not too slick to screw up attachment, no wax or slime needed to restore surface, just detergent.... low maint. Easier to touch up and repair scratches and dings.
Jay,
Yeah I read that and the depth of them need to tuned the expected speed. However they seemed to work down under where the boats were sailing in big seas.
For what it's worth I like a scratch free smooth surface polished with a non-silicone polish. The water sheets off the hulls, doesn't bead.
Eric are you saying the ARC's are painted? Who's twisted idea was that? 
I was at Robbie D's this eve and asked him what was on his Tornado....It wasn't gel coat.
Then...What do those guys know anyway.
I think it's more about surface tension, adhesion and low/high surface enrgy interfaces. A displacement hull has to push aside an amount of water equivalent to that it displaces at the speed of motion. The water 'wets' the surface to some degree and adheres viscously impeding the hull's motion. The water moves out of the way as fast as the hull goes, up to a point, at which the hull begins to plane. At that point the water is no longer 'wetting' the hull surface. So planing happens when the hull moves swiftly enough to exceed the capacity of water to move out of the way. Note that this is a pretty good analogy to subsonic and supersonic flight.
But there are other ways to reduce surface wetting, certain surface coatings for instance. Low surface energy coatings cause water droplets to bead up rather than spread out into a thin film, implying poor wetting and thus adhesion.
Jimbo
To further stir up the issue, the most applicable test data I know of, is rudder testing by some British grad students (Looks to me like they had too much free time). If I remember correctly, wax made no difference. The lowest drag and best flow attachment was with a 3200 grit finish. A real 3200 grit finish would be like a brand new camera lens.
So get to work. Try a high speed buffer, white plastic rouge, and continous water mist. Oh and be sure to clean the bugs off your hull after you trailer to the water. And the sand or grass off when you get it in the water. And Oh, maybe the scum, slime, and bits of stuff while its in the water.
Or you could just wax it to make it pretty and wash it before you race.
(For those of you whose native language is not English or have a hard time with humor, the last half of this was humor. In the real world, a 3200 grit finish on a catamaran might last until the dust settled on it. I would be hard pressed to maintain an average 600 grit finish at a regatta)
Carl
Carl, do you have a reference for that rudder testing?
Part of the study was on madforsailing.com or the Daily Sail with a link to the university library for the complete article. I read when it was a free website and did not think to copy it. Maybe someone with a subscription to The Daily Sail could find it for you.
I was told that someone found the article by going into the Online University Library search system. I can't confirm that.
There are actually lots of articles available on this subject however most are hard to for the majority of people to read. For example.
The Relationship Between Frictional Resistance
and Roughness for Surfaces Smoothed by Sanding
Researcher: Assistant Professor Michael P. Schultz
An experimental investigation has been carried out in the 380-foot towing tank at the U.S. Naval Academy Hydromechanics
Lab to document and relate the frictional resistance and roughness texture of painted surfaces smoothed by sanding.
Hydrodynamic tests were carried out in a towing tank using a flat plate test fixture towed at a Reynolds number (ReL) range of
2.8´106 – 5.5´106 based on the plate length and freestream velocity. Results indicate an increase in frictional resistance coefficient
(CF) of up to 7.3% for an unsanded, as-sprayed paint surface compared to a sanded, polished surface. Significant increases
in CF were also noted on surfaces sanded with sandpaper as fine as 600-grit as compared to the polished surface. The results
show that, for the present surfaces, the centerline average height (Ra) is sufficient to explain a large majority of the variance in the
roughness function ( ∆U) in this Reynolds number range. The results of this study have been published in the Journal of
Fluids Engineering
If you have access to an online search and retrival like a University Library. You will find many articles on the subject.