One of your defenses against the inevitability of Murphy catching you on a cruise is to have an adequate towing policy, as we found out last summer.
The annoying part of this story is that we had 2 unusual mechanical failures within a half hour that involved parts that were professionally installed less than a year before. The most serious problem was loss of raw water cooling as we were motoring dead upwind against an increasingly foul current. We lost time attempting to diagnose the raw water problem, thinking it was a blockage (sea weed, plastic?), but to no avail.
We attempted to beat to weather, but our estimated arrival was after 10:00 PM in an outer harbor that was exposed to a contrary wind direction that day. There were other complications that made it sensible to call for a tow that got us into the inner harbor at Cuttyhunk by 7:00 PM.
Bottom line: A towing policy can save you time and money when Murphy has your number.