My father and I were out sailing a while ago and I managed to flip our boat over. It was almost impossible to right it and, once we did, it was too swamped to sail back to shore. Luckily someone saw us capsize and sped out to tow us back to shore. After making it back to the beach and unplugging the drainage plug, it took about 30-45 minutes to drain all of the water out of the hull of the boat. During some point of this ordeal, the very tip of the bow was cracked and the two layers of the hull can be forced apart with enough muscle. The boat is still sailable, but I am worried about what might happen if I capsize again and am not lucky enough to have someone nearby to tow me in... Any advice about what I should do to patch it up and ensure that it wont sink?