Hard to say how serious it is but if there is FIBERGLASS deteriorating, or the fiberglass TABBING is letting go, that's something to repair post haste. Once you stop the leak (may need just caulking, may need a little more work) you can use CPES to repair some wood, fiberglass and/or epoxy to replace the rest. Probably a day of your time and $50-100 in materials--if you stop it now and fix it. If the bulkhead shifts and the chainplate lets go, that's gonna hurt.
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