Ramp operations can be carried out on the water using an optional power-down ramp and water dam configuration. The floor if I remember was sealed and also had one way drains installed, it’s a long time since I was on them. The RAF suffered corrosion from salt on one or so when they were originally delivered and that was traced to the crews delivering them to the docks and taking a car with them to drive back when they dropped it off, it was winter and snow / ice with road salt melted and dropped off the cars and then had several weeks to fester on the boat trip to the U.K.