RDS Below Deck 20 Gallon Starboard Tank Special Order - Ships When Available. Contact customer service for more information on Special Order items. Below Deck Shape Starboard 20 Gallon VSGSU Sending Unit Size36 12 X 8 - 6 X 19 Side Corners are radius bent, not welded All tanks have 14 NPT pickup, 1 12 fill, and 12 vent fittings Add 3 to height for fittings Gasoline only. No return fitting for diesel fuel Above Deck Tanks have vented caps with guage units Below Deck Tanks have electrical sending