Scale: Unknown. Model of a proposal for fitting a cylinder to the bottom of a ship as a shield for the propeller. The model is carved from a solid piece of wood and painted in realistic colours. The hull below the waterline is painted brick red with black above, and the deck is painted off-white. There is an aperture at the stern which appears to be provision for a rudder, which is now missing. The model shows a large diameter propeller tunnel with 6 horizontal vents on either side, which protects a single two-bladed propeller. The forward face of the model has a rectangular piece of wood attached to it and is painted black.