According to Jeff Dziedzic, who operates TowBoatUS Mystic out of Mystic, Connecticut, engine failures are a large percentage of tows, but other mechanical parts fail, too, leaving boaters stranded.
Dead Battery
Batteries have a shelf life, though it can vary by years depending on how they're treated.
Dziedzic says that many times calls for dead batteries come from boaters who are trying to get a little more time out of a fading battery. "Some boaters know their battery is weak but just haven't gotten around to replacing it," he says.
"Sometimes batteries die because boaters leave on the radios (stereos and VHFs) or maybe a baitwell aerator, which take a lot of power over time." Dziedzic recommends checking your battery (charge level, electrolyte level, connections) once a month.
Don't take the chance that it will die right when you need it.
If it's getting weak, replace it. Nearly all batteries are marked with their manufacture date or warranty start date, and wet-cell batteries typically last five years or fewer on a boat. If you're prone to dead batteries, it might be a good idea to take along a small jump pack.
BASED ON INTERVIEW IN BOATUS