User:Davelak/sandbox

A self-feathering propeller is a type of propeller that automatically ‘feathers’ when not under motor often found on a sailing yacht. The main purpose of a feathering propeller is to reduce the drag/resistance when under sail. In neutral the propeller blades will align with water flow to reduce the drag and turbulence when under sail. In order to achieve this blades need to be flat.

A feathering propeller is usually found with 2/3/4 and 5 blades. Darglow FeatherStream in the UK and SPW in Germany are two manufacturers of feathering propellers predominantly for the marine industry.

A feathering propeller is usually pitch adjustable meaning that an efficient blade angle is achieved in forward drive but also in astern improving close quarters manoeuvring. The propeller is feathered when under sail and gearbox is put into a neutral position. Laminar water flow and autorotation will cause propeller to feather. The adjustability of a true feathering propeller helps a user fine tune performance to their requirements.

A feathering propeller is one type of low drag propellers (folding propeller, feathering, self pitching) that is popular among sailors to improve all round boat performance whether racing or cruising.

The pro’s and cons for a self feathering propeller include: