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Sailrocket is no way inspired by Hydroptère, and in fact one might argue that they could not be more different: Hydroptere works by countering the heeling mome

Sailrocket is no way inspired by Hydroptère, and in fact one might argue that they could not be more different: Hydroptere works by countering the heeling moment caused by the force on it's sails and foils, with, basically, it's weight (it's weight times the distance between the center of gravity and the leeward foil) whereas Sailrocket works by having NO heeling moment and actually somewhat of a negative one, as the leeward hull can be seen lifting clear out of the water at speed. Hydroptere lifts out of the water by using foils, which are basically wings that work in water (at the air/water interface actually, which causes a host of problems) whereas Sailrocket skims along on planing surfaces, just like a powerboat or a windsurf. Sailrocket, as indicated in the article, owes a lot to Bernard Smith ( seminal work : http://www.amazon.com/Sailloons-Fliptackers-High-Speed-Sailing-Library/dp/0930403657 http://www.amazon.com/Sailloons-Fliptackers-High-Speed-Saili... ) Finally, Hydroptere works on both tacks (wind coming from either side) where Sailrocket only works on one tack. Some fascinating workarounds for this issues have already been worked out by Bernard Smith by the way.

bigiain 14y ago
+1. Look carefully at this picture from the article: http://www.wired.com/images_blogs/autopia/2013/01/ff_supercavitation5_large.jpg http://www.wired.com/images_blogs/autopia/2013/01/ff_superca... Check out the orientation of the "bridle lines" from either end of the wing, and the keel. When I saw that, it all went "click" in my head. This is just a wing tethered to the keel - like a kite, or a paragliger - the hull/fuselage and the spar and pods/floats are all just "unnecessary" bits, only used to hold the wing and keel in the required orientation to get up to operating speed. (I wonder if someone will build a version of this which jettisons all of the boat-like structure when it gets the keel and wing up to the speed needed?)
- jfoucher 14y ago
  AFAIK there is one project that tries to remove all "unnecessary" bits, although it's just a model: http://www.youtube.com/watch?v=1tEw_mlUh7g&feature=player_detailpage#t=231s http://www.youtube.com/watch?v=1tEw_mlUh7g&feature=playe... Just a kite tied to a "water kite"
  - bigiain 14y ago
    Cool! Thanks for that link. That's very close to the ideas floating round in my head right now. Something very similar to that, a super efficient "kite" (think more like the SailRocket sail or a glider wing), "tethered" underwater using this 50+knot cavitation tolerant foil technology. I'm guessing it'd need a fair bit of "stuff" to get it up to the speed where the wing and foil start to operate effectively, wich might either be jettison-able floats/spars, or perhaps some technique where it gets launched/towed up to speed - kind of like how big wave surfers use jetski tow-ins to get on to big waves at speed - I wonder what the world record rules would say about a 70+knot "sailboat" that need to be towed up to 50_knots to work at all?

bigiain 14y ago

+1. Look carefully at this picture from the article: http://www.wired.com/images_blogs/autopia/2013/01/ff_supercavitation5_large.jpg http://www.wired.com/images_blogs/autopia/2013/01/ff_superca... Check out the orientation of the "bridle lines" from either end of the wing, and the keel. When I saw that, it all went "click" in my head. This is just a wing tethered to the keel - like a kite, or a paragliger - the hull/fuselage and the spar and pods/floats are all just "unnecessary" bits, only used to hold the wing and keel in the required orientation to get up to operating speed. (I wonder if someone will build a version of this which jettisons all of the boat-like structure when it gets the keel and wing up to the speed needed?)

jfoucher 14y ago
AFAIK there is one project that tries to remove all "unnecessary" bits, although it's just a model: http://www.youtube.com/watch?v=1tEw_mlUh7g&feature=player_detailpage#t=231s http://www.youtube.com/watch?v=1tEw_mlUh7g&feature=playe... Just a kite tied to a "water kite"
- bigiain 14y ago
  Cool! Thanks for that link. That's very close to the ideas floating round in my head right now. Something very similar to that, a super efficient "kite" (think more like the SailRocket sail or a glider wing), "tethered" underwater using this 50+knot cavitation tolerant foil technology. I'm guessing it'd need a fair bit of "stuff" to get it up to the speed where the wing and foil start to operate effectively, wich might either be jettison-able floats/spars, or perhaps some technique where it gets launched/towed up to speed - kind of like how big wave surfers use jetski tow-ins to get on to big waves at speed - I wonder what the world record rules would say about a 70+knot "sailboat" that need to be towed up to 50_knots to work at all?