We'd like to add to our water capacity onboard Messenger, a Beneteau 38 1983. Any ideas? One water tank was removed to make room for an HVAC unit by the previous owner. We plan to remove that for our trip to the Caribbean this fall to make room for the old water tank. We're wondering about trying to get a new fibreglass one made. Maybe find storage somewhere else? We're also exploring water filtration systems. Any experience?