When returning to the marina one night, I solidly hit something submerged. Once back out into clear water, I dove to check for damage. I pulled a 3" x 2" piece of glass of the leading edge of the keel, about half way down the length of it. My proposed action is to weight until fall to pull the boat, then drill a small hole up into the glass to allow the water to drain out of the saturated glass, then repair as necessary. I feel it's best to take this course since the boat has been in the water for a week now that the damage has been done and the glas is most likely already saturated. As a side note, on the piece I pulled off, I can see a blunt spot on the glass where I hit something. I am thinking it was a large submereged log. I did not see any physical damage to the keel itself.