Water propulsion was via a small propeller mounted at the rear of the hull.

It was almost as though the small propeller were single-handedly trying to keep the crippled chopper aloft.

Two small propellers with variable pitch were used for thrust and yaw control.

Just a simple drive to a small propeller.

At each end was a small propeller.

Some impellers are similar to small propellers but without the large blades.

The first design, which flew with small propellers, crashed into a moat during a trial run.

The sound of small propellers and an underwater signalling device could be heard for a short while after the explosion.

A small propeller drove the craft and could be moved left and right for turning.

In water, the vehicle was propelled by a small three-bladed propeller mounted at the rear.