The patent. US 1,001,260, "Marine propulsion mechanism", filed 16 September 1910 and granted 22 August 1911 to Ole Evinrude (born in Vossestrand, Norway, emigrated as a child to Wisconsin), assigned to the Evinrude Motor Company he had founded with his wife Bess.

Evinrude did not build the first outboard motor, and the priority is not close. Cameron B. Waterman's US 851,389, "Boat-propelling device", was filed 6 December 1905 and granted 23 April 1907 — roughly five years ahead of Evinrude's filing. Waterman tested his engine in 1905 and sold detachable outboards commercially before Evinrude built his first. There were earlier attempts still, going back to electric-powered detachable units in the 1890s. What Evinrude has an unambiguous claim to is the market: launched in 1910, his company sold over a thousand units in its first year and turned the outboard from a curiosity into an ordinary object. Being second to the patent and first to the market is a common shape in this programme, and it is worth stating plainly rather than resolving in the inventor's favour.

The ice-cream story. The popular origin tale is that Evinrude rowed across a lake to fetch ice cream for Bess, that it melted on the way back, and that he resolved to motorise the boat. It is repeated everywhere, it may well have a kernel of truth, and it is not documentation. It is included here as folklore, labelled as folklore. The patent record says nothing about ice cream.

Why swivelling the whole unit is the real idea. An inboard installation separates the two jobs: the propeller makes thrust in a fixed direction and a rudder deflects the water leaving it. That works, but it needs a hole through the hull, a watertight gland around the turning shaft, a fixed shaft angle, and a second control surface. Swivelling the entire drive collapses all of that into one moving part — steering becomes thrust vectoring. It also means steering authority disappears the moment the engine stops, which is the outboard's genuine weakness and is why a drifting boat with a dead outboard cannot be steered at all. Step 12 shows the trade honestly: past about 30° you are turning hard and going nowhere.

The tilt is not a convenience feature. Small boats work in shallow water, over sandbars, and get dragged up beaches. A fixed propeller below the hull is destroyed by all three. Tilting the leg is what makes a motorised small boat survivable in the places small boats actually go, and it is why the two adjustments in step 1 belong in the same patent — an outboard that could steer but not tilt would have been an interesting failure.

Boats

Blueprints (2)

Outboard Motor

Clinker Planking