I think the hydraulic tank for the Batfish is right in the control room to the right of the "Christmas tree". There are also two switches to operate the pump motors, a hydraulic pressure gauge, an air pressure gauge, and one or two site tubes to monitor oil level. I tried turning the valves to the site tubes and they were frozen in place. The tank looks like it would hold about 10 to 15 gallons and appears to be empty.