I had a Wellcraft Sportsman that almost sank while black fishing off Hatchets reef. The cause was a common one and an easy fix. One of my plastic thru hull fittings fell out. The pictures are of my present boat here in La.

My Glaicyer Bay is 12 years old and the plastic thru hulls are not only being eaten out by the salt water but I have been getting a good amount of water on the port side. Each side was getting water but the port was worse.

The darker area around the upper hole is caused by water seeping through and discoloring the 5200. The second one down seemed to be OK. The large one in back, below the water line, was the big leaker. I have 2 good bilge pumps on each side (4 total) and they kept me out of danger. The constant water problem had me bugged for a while. Problem being taken care of!!!
I need 10 new fittings at around 40.00 each with new hoses and the decks have to come up but the new stainless steel ones will assure me this problem will never happen again. I advise all of you to check your thru hull fitings and if any question replace them with stainless. Bronze is best and a little more expensive and it does not add to the decor of the outside of your boat.
The best thing to do is automaticaly replace plastic ones. I wanted to do this last year and was forced to do it now. Stay safe.
Life is Good!