For the nation's 12 million boat owners, Labor Day weekend was the last blast, with many enjoying the end-of-summer boating ritual with family and friends aboard, according to Boat Owners Association of The United States (BoatUS). The national advocacy, services and safety group cautions, however, that boating traffic and complacency have increased safety concerns every year.

BoatUS's nationwide on-water towing fleet, TowBoatUS, often forecasts an increase in number of boaters on the water during the three-day Labor Day holiday period. "Fourth of July, Memorial Day, and Labor Day are the 1-...