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Solved problems · Deck · Crew answer

How do I stop a hatch or portlight from leaking?

Hatch and portlight leaks come from a worn closing seal, failed bedding between the frame and deck, or a loose lens. Find which one with a hose before you replace anything.

Symptom

Water drips from a deck hatch or opening portlight in rain or spray, either when closed or around the outside of the frame.

Likely cause

Opening hatches and portlights rely on a rubber closing seal that flattens, hardens and cracks with age and sun. The frame itself is bedded to the deck or cabin side, and that bedding fails over time. Some frames also leak at the lens or at frame joints. Latches that no longer pull the seal tight let water past too.

Stop now if

A lens is cracked or crazed on an offshore boat. A broken hatch or portlight in heavy weather can let in a lot of water, so replace or cover it before going offshore.

The fix, in short

  1. Test with a hose. Close the hatch or port and run a gentle stream around it while someone watches inside. Note whether the water comes through the closing seal, the frame-to-deck joint, or the lens.

  2. Replace a tired closing seal. If water comes past the seal, remove the old seal and clean the channel thoroughly, then fit the maker's replacement seal following their instructions.

  3. Adjust the latches. Latches that don't pull the seal tight let water in. Adjust or replace them so the lid closes evenly.

  4. Rebed the frame if needed. If water comes around the outside of the frame, remove it, clean the opening, seal any exposed core, and rebed it with a suitable marine bedding compound. Lewmar's portlight instructions specify the sealant type, thickness and screw torque for their frames.

  5. Replace crazed or cracked lenses. Crazed acrylic is weaker and leaks at the edges. Replace the lens or the unit.

Written by Sailor Cruiser crew. General guidance, not an inspection of your boat.

Equipment involved

  • Deck openings: Opening deck hatches, portlights, closing seals, latches, lenses and frame bedding

Related guides

Sources

Background reading we checked while writing this answer. The wording above is our own.

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