SloopJonB is right. Don't put a bandaid on it, fix it right once. That hatch box will be secured by screws from underneath. If you take it off it will be easier to also refinish the box on a work bench, remove hatch from box to reseal and then install the whole assembly back to the deck. If there is enough board width router a groove in the bottom to accommodate more sealant on the install. Good time to replace the old fasteners too.