this happened to a friend on a delivery of a BRAND NEW SWAN from florida up to annapolis. full moon goo weather on the atlantic, crew were down below all asleep. denny gets up to use the head, steps into a foot of h 2 0. calls all hands, mayday to USCG, they are 50 miles off the mouth of the chesapeake . (no bilge pump hi water alarm on a $650,000 boat. ) frantic scramble to check where's it coming from. it's salt h 2 0 , not fresh! crew crawling under cabinetry, pulling up floor boards. no thru hull diagram supplied. on a $650,000 boat. USCG sends a helo w a carolina moon, new swan boat is in real trouble, may be a crew evac. water is fast approaching engine-kill height, crew wants to try to rig raw water pump for engine to use as extra bilge pump but figures it's too dangerous due to flotsam in water etc. then someone discovers that the PLUG for the knotmeter instrument has come out, thus flooding the boat. knotmeter plug is still attached, they re -inserted it. by now a USCG boat has arrived and supplies hi volume electric pumps. uscg stood by for massive pumpout . boat engine was saved, swanboat made it in under her own power. a reconstruct of the cause: the sensor for speed was mounted right past the turn of the hull, with instructions to twist it in then and then lock the lever down. the prep crew had twisted it in but han't locked the lever down. it popped out. the boat flooded. the new owner WAS NOT PLEASED. when my dockmate denny related this to me, i promptly made a diagram of all the thru hulls on my boat, and installed a double bilge pump switch with a piercing high water alarm.