I am a machinery technician in the Coast Guard and am stationed aboard the CGC Bainbridge Island, a 110-foot patrol boat. During our recent patrol in the Caribbean, we had a jacket water-fitting break on the bottom of one of our main propulsion engines. The engineering officer gave the captain a one-hour repair time due to the time it would take to drain 65 gallons of 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 oil from 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 idea from a Car Talk Puzzler. Thanks for the help.