KNOW YOUR SYSTEMS. No one thinks much about their onboard plumbing systems until something goes wrong; maybe the pump is cycling on and off, the water tastes funky, the holding tank overflows, or your bilge fills up with fresh water the day your vacation starts. If you are one of those sailors who has lived in happy ignorance of the intricacies of boat plumbing, you ll certainly get something out of this slim volume. Payne gives us chapter and verse on everything from bilge pumps to holding tanks and watermakers. There s plenty of good advice for the owner who wants a better understanding of these essential but often overlooked systems.