Published in: Thursday, 07 October 2010
Features > L'Hydroptere (Page 1/3)


L’Hydroptere is a marvel of engineering that’s been over five years in the making, and it’s now the prototype for a set of yachts that will shatter round-the-world records

I have been at sea in many of the fastest powerboats on the water. But that experience was nothing compared to travelling at 36 knots under sail, a seemingly impossible speed under sail using wind power alone. The day we were out at Cowes in the Isle of Wight the wind was only a moderate 15 knots. It is quite incredible to be sailing at this speed, but what is amazing about this foil trimaran is that it all seems so easy and natural. This boat is the result of 15 years of development and trials, and it now looks as though the French team behind L’Hydroptère have found a good solution for high speed under sail.

L’Hydroptère is the fulfilment of the dreams of Alain Thébault, who commented: “It has been a long hard development programme and we have suffered many breakages along the way. You can imagine the stresses involved when using wind power at these extreme speeds, but we now think we know the answers.” Earlier this year the crew of L’Hydroptère set a new world record under sail at a shade over 51 knots but they have gone even faster. Thébault reckons that they were travelling at 61 knots when the boat capsized during trials!

Hydro 1

This is not only the world’s fastest sailboat, but also the most exciting. On board everything is spartan and functional, with no room for luxury. The format is a trimaran with a beam of 24 metres on a length overall of 18.2 metres. The centre hull is long and thin, while the wing floats are like those on a flying boat, with a step in the underwater surfaces to reduce resistance. The angled foils on which the main weight of the boat is carried when foil-borne are attached just inboard of these floats. At the stern of the main hull is a T-foil that also acts as the rudder.

To power L’Hydroptère, there is a towering semi-wing mast that supports a conventional sail plan comprising the fully-battened main, a staysail and a jib. The mast is 28 metres high and supports a total sail area is 365 square metres. This full area can only be used in lighter winds and even in the 15 knots of wind during the sea trial, we had one reef in the main and only the staysail in use. The rigging has been kept simple, with twin stays at the sides running out to the floats, backstays and of course the forestays on which the self-furling foresails are carried. 

The foresails are handled by a single rope sheet and the main sheet is taken down to a carriage on a track, with most of the sheeting of the main done by adjusting the position of this carriage. When the yacht is sailing at speed, every rope is as tight as an iron bar, and when you consider the speeds involved it looks very fragile – but it does work.

Hydroptere Graphics

Hydroptere Forward View Of Foil

Hydroptere Foil Aft View