This propeller is a left hand rotation

It turns counterclockwise

This propeller is a right hand rotation

It turns clockwise

Determining propeller rotation is by looking from the rear (AFT) of the boat forward to the front (BOW) of the boat.

The most common propeller is right hand (clockwise) rotation. The cutting or leading edge of the above propeller is on the right hand edge which is the lowest. The highest edge above is called the trailing edge. This edge may also have a rolled section which is called a Cup

Above: Counter rotation propeller rigs (both left and right hand propellers fitted)

Above: Dual right hand propeller rig

Above: Volvo Duo Props