Small boat, small problem. But also, small comfort and small speed, which means a long crossing... On boats over 40', gennakers, asymmetric spinnakers and downwind sails require considerable physical effort to handle. Add to this their cost, which delights manufacturers but dismays users, and you quickly come to the decision to do without them, or rather, not to use them at all...
Finding an easy downwind sail for multihulls
Doing without gennaker is one solution, but... it's a solution with three major drawbacks:
- Multihull mainsails can rarely be overhung more than forty to fifty degrees from the boat's centerline. When the battens holding the leech come to caress the standing rigging, it's the beginning of the end, for both sail and battens. The damage caused will be very costly.
- Head sails, jibs and genoas, which are often very modest in size, are also difficult to maintain, as the spinnaker pole is almost always absent.
- The result is a low projected surface area, which generates a speed well below the boat's usual performance. And that's annoying...
An idea born of sailing
All these inconveniences haunted the mind of a tourdumondist sailor. Countless were the hours on watch that this ex-boatbuilder spent observing these not very pleasing sights. So, in the course of his long tour of the world, he ended up designing a sail specifically for cruising catamarans sailing "portatif", as the philosophers say. A Speejonk between +125 degrees and -125 degrees from the actual wind!
Concept validation with a 120-square-meter prototype
After tests on a thirty-centimeter sailing model, a generous sponsor made it possible to build a full-scale prototype. Our inventor then set about finding partners to industrialize and market this product (described as "brilliant" by the number 1 cruising catamaran manufacturer, who eventually abandoned it...).
How does Speejonk work?
The sail has a surface area around 1.6 times that of the mainsail, three horizontal battens at the top and windows at different levels to maintain forward visibility.
Unused, it's stored on a simple genoa furler - albeit a smaller one, as it requires less effort - with a horizontal shaft, stretched between the two bows.
Unfurling is a breeze, as you haul in a spinnaker halyard and give the furling line some slack.
No trimming, no gybing, and the catamaran advances at about half the true wind speed (10 knots with 20 knots of wind).
This sail can be reduced "at will" to adapt to any wind force. We take the precaution of reducing to the next "window" so that we can always see ahead.
When it comes to wearing (or not wearing) the mainsail, everyone will adopt the attitude that suits them best. Without mainsail, it's much more comfortable and safer. With mainsail, it's more rock'n'roll and faster, especially in points of sail between 125 and 150 degrees from the true wind.
It should be pointed out that this sail is completely flat, and that the battens are used to hold the leech rings, which are there to give surface area at the top, where the wind speed is greater.
Note that in the event of damage, this sail, even reduced to the size of a storm jib, keeps the boat downwind in the absence of a pilot.
A marketing attempt
A contract was signed with a manufacturer of deck fittings, covering the registration of a patent and the undertaking of certain commercial actions to promote the product. However, the manufacturer did not undertake to promote the product. The agreement contained very clear clauses stipulating that the patent should revert to the inventor in the event of poor sales...
Commercial imbroglio...
Today, this unused patent is available to anyone with an interest in it. It is still valid for a period of 9 years, and the inventor offers its use to anyone interested in exploiting it. He is open to all forms of negotiation to prevent the Speejonk from falling into the public domain.
