Is the hinge loose on the lid it self or where the lid attaches to the boat ? Most lids are either wood and fiberglass glass on the out side and a wood core, or are all glass, or as in the case of my boat a Hydra-Sport it is wood with a plastic shell that wraps over the bottom. Hydra Sports and Stratos where both made by hydra sports in the early days, and there are very few differences between them.
If you sure the hatch is solid wood that you can replace the whole lid with new pressure treated 3/4" plywood, don't go trying to just replace a piece of it it will not likely hold. If its a glass lid no wood or wood core with glass over it you can grind out the glass covering the wood, and the sand that area very smooth and clean with acetone, then put in a piece of very dry pressure treated wood, or a resin sealed piece of exterior grade plywood. then glass back over the new wood.
If its loose on the cap side , the boat and not the lid, it may just be loose screws or rivets, may not be bad wood, or glass, and if loose in the glass, you could always go up one size in rivets, make sure they are all aluminum ( NO STEEL ) parts
Pictures would help a lot to give you more info, or seeing in person would be even better in helping you determine the best repair route.
If you do take pictures make sure you get some clear close up shots , and from different angles with good lighting
Hope this helps
