Hughes 26?

Smarticle! You could rig something like that without much expense. Just a triangle of fabric back from the pulpit to the beams might give an idea about how effective it is.

Was out sailing the other day and got wallowing downwind. Pumped about a litre of water into the boat via the daggerboard slot!! Can I joint the club now? Do I get a U-boat commander hat or barge? Dive! Dive!

 

On my Bucc I just made a rectangular DB and fitted a rectangular box around it up to the level of the seat stringer and incorporated the box into the front part of the seat.
The board box was sealed top and bottom with a rigid f/glass seal, configured closely to the 0008 symetrical foil shape of the DB and NO slop in the box. The DB had a 1"x2" wooden stop on the top,which closed off the box and made a nice handle to move the board with and was flush with the seat when the board was down. With the board up to a mark, the blunt end of the board matched the bottom face of the keel and allowed grounding without picking up sand and gravel.
Never had a problem with water in the boat. (only beer).