Jonbuoy

A specialised man overboard recovery device designed to provide buoyancy and visibility to a person in the water. 

A Jonbuoy is a self-contained, inflatable man overboard (MOB) recovery system used on yachts and other vessels to assist in rescuing a person who has fallen into the water. Typically stored in a compact canister mounted on the stern rail, it is deployed by pulling a release mechanism, which inflates the buoy automatically. The Jonbuoy usually consists of a floating horseshoe or cradle, a high-visibility flag, a light, and sometimes a drogue to reduce drift. Some models also include an integrated lifting sling to aid in hoisting the person back aboard. 

The Jonbuoy is an alternative to traditional lifebuoys and is designed to be more compact and effective in rough conditions by providing better visibility and stability. It is particularly useful for short-handed crews who may struggle with traditional MOB recovery methods. Regular maintenance, including checking the inflation system and repacking the unit correctly, is essential to ensure reliability in an emergency.