Outboard Motors: The Little Engines That Could

An outboard motor allows you to buzz swiftly across most any body of water. Dive into Groupon’s guide to learn more about this remarkable invention.

"Don't Row! Throw Away Those Oars! Use an Evinrude Motor!" So ran a 1909 slogan for one of the world’s first outboard motors. Today, the concept needs no advertisement, and you can spot outboards along any waterfront: sleek metal units on the backs of small boats. Inside each is a piston-driven, internal-combustion engine, quite similar to those that power cars. But how does a pile of metal and gasoline literally propel a boat across the water? The process begins with the basic principle of thermal expansion, converting liquid fuel into a hot vapor. The fuel is released into a chamber where it is mixed with air, compressed, and ignited. As it burns, it turns into gas whose expansion forces a piston down. Each piston is connected to a crank that turns with the piston’s downward force. The crank drives a shaft, which is attached to a propeller. The propeller pushes water backward and, consequently, the boat forward. To change directions, outboards are mounted on a simple pivot. Due to this power and ease of control, outboard motors have become the most common means of powering small watercraft.

The first removable boat motor was electric, and could also be used to propel a bicycle or other land vehicle—in 1881, the Parisian inventor Gustave Trouvé reported that his battery-powered motor could send a tricycle with rider whizzing off at 12 kilometers per hour and three passengers just a little slower in a small pleasure boat he dubbed Le Téléphone for its unprecedented speed. Two decades later, Yale law student Cameron Waterman, inspired by his bicycle’s removable electric motor, adapted a motorcycle engine to nautical needs and introduced the term “outboard motor” to the world.

The real gas-powered revolution began around 1910 with Ole Evinrude. One story holds that the young machinist was on an island picnic with his sweetheart when she expressed a wish for ice cream. As he rowed to shore and back, the frustration of watching the ice cream melt in the heat and completely ruin the little chocolate-syrup heart he’d drawn reportedly inspired him to set about developing an inexpensive, easy-to-manufacture engine. He and his sweetheart (by then his wife) marketed the engine by mail, and the rest is history—the Evinrude logo continues to line lakes and shores today.