Saying “my boat has no leaks” equals saying “I’ve never lied”. Some leaks show up soon after the topside gets wet. Other leaks take time to show up. Aboard Spartina, water collecting on the cabin sole below the mast collar meant it’s time to replace the mast boot. Water stains around port lights and deadlights meant it’s time to remove and rebed them all. Water collecting in a single wine glass in the outboard starboard locker above the galley stove continues to confounds me. This “wine glass leak” has temporarily ceased on the starboard side and has begun to leak exactly awthwartships on the port side electronics locker.
Deck leaks are worrisome, especially if the sailboat is built with a cored deck (most are). Spartina was built with an end-grained balsa cored deck. Water leaking past deck fittings into a core can cause deck delamination. Any deck fitting inside the lifeline stanchions can leak into the balsa core. These include a windlass, jib tracks, main sheet blocks, teak handrails, and a deck collar. S/V Spartina was built such that lifeline stanchions and other peripheral fittings bolt through non-cored solid fiberglass, thus don’t pose a threat to core rot. Also, solid fiberglass trunk cabin sides isolate the cabin top from the side decks. This prevents leak migration from the cabin top to the side decks, best I can tell.