this is a bunji with a piece of PVC surrounded by foam. It helps put a side load on the daggerboard to help keep it where you leave it in the hull. Works beautifully and is used on the Nacra 6.0 and 5.2
Hobie used to use the same system on the Tiger dagger boards. It worked well but if your boards push down almost flush to the deck then the tube can slip over the top over the board - so next time you raise the board there is nothing to hold it up. They are now using a small rubber wiper that applies slight side force to the boards. It is screwed into the deck at the mid point of the board. This system works very well can could be applied to any boat with dagger boards. The parts are available as an inexpensive kit. This system is very similar to how the Nacra 20 dagger boards are secured.
