The fuel tanks on a River Rover Mk4 hovercraft are used not only to hold fuel but to balance the hovercraft so we can use less of that fuel as we go – and we can go for 8-10 hours depending on the conditions. Did you know diesel fuel actually gets quite hot as it goes to and from the engine many times with only some of it getting used each time, so these tanks have a lot to deal with. They have to be tough to resist the inevitable knocks but light enough not to weight the craft down, and they have to last the lifetime of the hovercraft . We only use carefully selected marine grade tanks and all fuel enclosures are themselves fuel and water tight to act as a second fuel bund and to protect the environment from any spills.