This is a video of the idea of the daggerboard.
It is placed foreward of the saloon/sleepingroom therefore it does not to any great extent interfere with living conditions.
When lowered there is space in the daggerboard case for the top of the daggerboard to mowe foreward thuse the bottom part can mowe aft creating the same effect as an crumple zone in a car. On the wind Exlex might mowe with 3 knots or 5 km an houer compared to 1oo for a car still the crumple zone about the same lenght.
Enjoy, regards Yrvind