It's no fun to roll out of your berth at 4:30 a.m. and stumble toward the shower only to find your boat's water pressure is producing little more than spit. Likewise, if you're ever stuck in some backwoods marina where the only excuse for a fuel pump is a couple of rusted 55-gallon drums, it would be wise to consider a GP301-12 Pump from Reverso. This pump is relatively compact, inexpensive, and well suited for priming filters and transferring diesel fuel, water, and antifreeze. It moves fluids at three gallons a minute and generates 55psi of water pressure, which is equivalent to your home shower. Most pumps' internal rubber impellers keep fluid flowing but wear down over time. And if the pump runs dry, the impeller will fry and can derail the pump.