Looks like Sailrocket mark 2 will be unveiled in a couple of days:

www.sailrocket.com/stories

I particularly like this part:
“The fact is that in the world of outright speed sailing, there is nothing of real interest to us below 50 knots. 50 knots has to be a minimum cruise speed for our next boat and it must be able to do it in a wide range of wind and sea states.

Best of luck to them, I really hope that they give the leaderboard a good shake up.

If it gets the record of the teabaggers fair play.

The project seems to be 100X more professional than last time. It looks like they have addressed all the key issues. 55 should be a doddle. 60+ ?? I would not be surprised.

looks like they are going to try "supercavitating" foils. I would be surprised if they worked. I hope they have a set of normal foils as a backup.

i'm with slowy here...
i would be surprised if they can overcome the high drag those foils have at low speeds to get to a speed where they would actually be an advantage.

until they get up to speed to actually work in a supercavitating mode they will "only" be ventilated foils anyway. just like a kiteboard is a ventilated foil.

"normal" foils with a lot of rake to delay cavitation inception would have been my choice... but i guess they have done their numbers.

it's gonna be a good show to watch for sure.
good luck to them.

Boogie

pardon my ignorance guys (Slowie & Boogie) but does a super cavitating foil have a really thick / flat leading edge and does it work like those torpedoes that effectively create an air bubble (high or low pressure?) in front of itself thus reducing or eliminating drag completely. The science / mechanics behind it all is beyond my brain's limited capacity. I will google it and do some research.

10 minutes later.......................

Okay I'm an expert on the matter now
Firstly a few corrections above;
It's not an air bubble but rather a vapour bubble that's created
it's only the leading edge or head of the torpedo that is in contact with the water with the vapour bubble being created entirely around the trailing body
& it only really works effectively at speeds greater than 100knots.

So in theory at what speeds could a supercavitating fin effectively be utilised (+70knots , greater?) and would you require mechanically means to get you to effective operational speeds initially as drag would be too difficult to overcome as noted above?

Haven't seen the foils sail rocket will use but foils designed as supercavitating foils (as apposed to normal foils that are supercavitating ) generally have a very sharp leading edge, a thick trailing edge and basically look like a curved wedge.



on a sub cavitating foil approximately 2/3rds of the lift is from the low pressure side and 1/3 from the high pressure side. If you loose that lift due to ventilation/cavitation your fin has only 1/3 the lift it had the instant before ventilation/cavitation.=>> wipeout. Actually because of fin twist etc usually not all the foil looses lift so it is often not quite as dramtic.

Thanks YoYo. found a great discussion here as well including Sailrocket #1 discussions. www.seabreeze.com.au/forums/Windsurfing/Gps/Supercavitation/#259276

Apologies for hi-jacking thread too guys.