[warthog5]

While that worked for ned2nav, it would be best to clamp the tank down. I did it by screwing 2X2's across the tank and into the deck. I will fill the screw holes with epoxy. If your tank is close on the measurements to get the max size tank, the movement of the foam could cause you having to remove the tank and start over due to the foam lifting the tank and then the hatch not fitting corectly.