I am a machinery technician in the Coast Guard and am stationedaboard the CGC Bainbridge Island, a 110-foot patrol boat. Duringour recent patrol in the Caribbean, we had a jacket water-fitting breakon the bottom of one of our main propulsion engines. The engineering officer gavethe captain a one-hour repair time due to the time it would take to drain 65 gallonsof jacket water and then refill it again after the repair. In a moment of revelation,I remembered a Car Talk Puzzler where a vacuum cleaner was used to keep the oilfrom draining from an engine while the oil plug was removed.Immediately, I grabbed the shop vac and pulled a vacuum on the jacket water system,which kept the water from draining out long enough to replace the broken fitting.We were underway in 15 minutes. I was the man of the hour.I almost took credit for it, but eventually I told everyone that I got the ideafrom a Car Talk Puzzler. Thanks for the help.