Originally Posted by svHyLyte
Something I have not seen mentioned is the need to have a reliable manner of securing the companionway drop-boards in the event of a knock-down, or capsize/roll-over during bad weather. In the Fastnet ('79) a significant number of yachts that were knocked down or capsized lost unsecured drop-boards that "fell out" and allowed major flooding even though the boats quickly re-righted themselves. Our drop-boards are heavy 3/4" in. thick teak plywood. To secure them we use 1/2" shock cord that attaches to pad-eyes on either side of the base of the companionway and can be pulled over hooks on the interior sides of the boards. The cord is strong enough to prevent the boards from dropping out under their own weight, but not so tight that one cannot free them reasonably easily. When off-shore, we generally keep the lower drop board in place, and secured, against the possibility of an errant wave coming aboard, which has happened from time to time. In the night, we always have both boards in place, and secured, although the hatch cover, under the dodger, may be left open for air circulation.
I do the same, keeping the bottom of three drop boards in. Even if the cockpit area were to fill, it would keep most of the water from running into the boat. And, yes I have also had an occasional weird wave break into the cockpit. Never filled up to the boards, but it is definitely possible. The bungee idea seems like a good one. Might be worth mentioning that there is a much larger danger of losing them/it in boats with tapered drop boards which come right out as soon as they are lifted a couple of inches. If a boat has this type, it would be even more important to devise some way to assure it can't escape. One suggestion above is to have a second emergency hatch. It probably is a good idea to have backups for any hatch/portlight/dorade, etc. One thing I left off the original list is the dorade vent plugs.
I have pieces of plywood for all openings, including sidelights. They have long carriage bolts/wing nuts with wood blocks to span/catch on the back side, all pre-drilled and ready to go.