Bridgedeck clearance on a catamaran invites a wide difference of opinion among sailors. But what we all agree on is that good clearance is very important for the seaworthiness and comfort of a catamaran. See what Stephen has to say in the video at right.
Avoiding slamming or pounding of waves against the underside of the bridgedeck, can make all the difference for the comfort of the crew and safety of the vessel. The slamming phenomenon can both be nerve wracking for the crew and damaging to the boat.
As a rule of thumb, we believe that clearance of between 5 and 6% of the LOA of the catamaran is good.
According to Sackville Currie, bridgedeck clearance (the height of the bridgedeck above the water) is crucial. Read his article that explains why the bridgedeck clearance is so important.
The video at right was taken between the hulls of a Lagoon 450S while underway. Conditions were rough with following seas of 6-8 ft in Hawks Channel between Marathon, FL, and Key West. Wind speed was between 30 and 38 knots and boat speed between 9 and 14 knots.
Note that with good bridge deck clearance, there was very little slamming even in very choppy seas and moderate gale force winds.