Top Windows
I assume that you are referring to the top hatches. (Although some Beneteaus had fixed lights in some models such as the 321.) More often than not, the leak is not the gasket or seal but coming in around where the hatch is bedded into the deck. You can remove the hatch then clean and rebed with 3M-5200 or similar. While you have the hatches removed you can replace the Plexi, a DIY project if you are handy. They are probably Lewmar Ocean hatches although I am unsure of what was used on French boats. Plexi is available through Lewmar or any Plastic shop. If it is a fixed window, just remove, clean off old adhesive from deck opening and install new Plexi. Cracking or crazing appears to be caused by exposure to the sun. Consider getting some Sunbrella hatch covers in hot climates like Israel. Good Luck!Jon McClain