The upper 18" or more (45cm) of the trailing edge of the board is quite thick. It might actually be the same as the height of the daggerboard well in the hull (not sure). Below that thickened edge, the board has a standard sharp trailing edge. When raised normally for downwind sailing, the board is allowed to pivot in the well. When fully lowered for upwind sailing, the board fits tightly in the well and is not allowed to pivot.

The next question you are going to ask me is if they point downhill or uphill when raised...I confess that although I spent a full weekend on one last weekend I neglected to notice - but I have it on high authority that they point downhill. While reaching if raised, they pivot back and forth with the wave action but I doubt they have any intent for reaching.