Leaking portlights are a common sight on older sailboats, and they aren’t uncommon on newer ones. Often the owner does not notice small leaks, but over time they get worse and worse until they cannot be ignored. This example is particularly bad: the interior wood trim is saturated, and there is no getting away from the damage that has been caused.
The visible damage is bad enough, but the damage you don’t see can be much worse, especially on boats with cored decks. The water seeping around the portlight’s mounting flange will eventually start to wick into the core material, where it will start to spread. In the parts of the country where freezing temperatures are common, the water turns to ice and expands, forcing the laminate apart and allowing in even more water, which will then freeze and force the laminate apart.
Sometimes owners will make a futile attempt at a “repair” by squirting a bit of goo around the outside of the frames, which looks terrible and does absolutely nothing. This portlight should have been removed and correctly re-bedded long ago. Problems like this, if left unchecked, will seriously affect the resale vale of the vessel.