Leaking windows are inconvenient because they let the water that is supposed to remain on the outside into places it shouldn't be. Oh, its aggravating enough that you might have to try to sleep on a wet mattress, but that's hardly the least of your problems when you have a leaky boat. The real kicker is when those leaks cause a lot of damage, as they are wont to do, that cost you a whole lot of money to repair, and even more money when you go to sell the boat if you don't.

Leaky windows are a serious problem not only because of the costly damage they cause, but also because all too often the source of the problem are design errors which are costly to correct, if they can be corrected at all. Leaky windows are a serious problem because it is such a widespread problem, occurring in top of the line as well as bottom of the line boats. Leaky windows are a problem because if you buy a boat that has them, and the problem cannot be corrected, you are going to take a big bath come time to sell your boat.

Leaky windows are also common place in the express cruiser which has no superstructure, where instead long, low windows are set into the side of the foredeck. The above photo shows a Sea Ray with an 8' long window which essentially holds up the fore deck. Lacking any bulkheads or frames beneath, all you have to do is jump down onto the foredeck from a high dock and you will bend and open up the joints in the window frame, and then the leaking starts. On this particular boat, the owner had caulked the sliding windows permanently shut and attached plastic coffer dams under the windows in an effort to keep the water out. Needless to say, it didn't help much. Beware of cruisers with long windows that hold the deck up.

The bottom line to this story of leaking windows is that leaking windows cannot be prevented, and cannot be repaired, unless the overall structure is properly designed. That includes not just the house structure and window frames but the decks as well. If the side decks are cantilevered inboard without adequate support underneath, then the side decks are going to flex, once again tearing everything open.