At Grand Pavois 2016 we discovered the EOS 54 a 16.45 m catamaran designed for fast cruising. During the visit, we came across a singularity: this catamaran is equipped with only one daggerboard in its starboard hull. Nothing protrudes on the deck of the port hull. Interested, we wanted to know more and contacted the architect of this model.
Christophe Barreau explains this atypical choice:
"In his specifications, the owner of the EOS 54 asked us for 6 cabins, 5 of which were doubles. We tried to turn the plans upside down without succeeding in accommodating all these cabins while keeping 2 daggerboards. Indeed, the daggerboard wells are rather cumbersome and hinder the layout.
On the other hand, I had seen a 40-foot catamaran racing with only one daggerboard. I contacted the owner of this boat to get his opinion. He told me he had never been bothered by this layout. So we adopted it on the EOS 54: the starboard hull with a vertical daggerboard and nothing under the port hull.
The drift in the center of the float
On the EOS 54 we have chosen to put the daggerboard in the center of the float, almost in its axis so that it comes out deep. This eliminates the turbulence zone at the surface as seen on catamarans where the daggerboard, stuck to the planking, dives right to the waterline.
We also chose to increase the aspect ratio to give more lift to this single fin. It is therefore deeper than if we had 2 daggerboards.
An upwind delivery that validates the concept
The delivery trip to the Grand Pavois, the first sailing trip from Lorient to La Rochelle while sailing upwind, validated our concept. The boat behaves well without one side being more penalized than the other.
On a classic catamaran with two daggerboards, I recommend sailing with both daggerboards down (more or less low depending on the sea conditions) in order to distribute the stresses on both hulls. On the EOS, we'll sail with only one daggerboard lowered a little deeper."
