Miss-staying in a seaway:

If your boat miss stays in a seaway and gets sternway on, don’t jam your helm hard over. Keep it amidship, and try and get your headsail a-back; then slowly put your helm over. It is a dangerous practice to jam a helm hard over when a boat is making a stern board in a seaway, as you are liable to damage the rudder or drive her counter under. If a centerboard boat, pull up the board, as this will help her to fall off.

REEFING.