I have a few of them dotted around the boat, especially in the heads. They are some sort of electrical fitting and appear live. What does anyone else use them for ? Where can I buy the corresponding plugs ?
Yup, they are the Continental smaller-than-car-cigarette-lighter-plug 12v sockets, into which you can plug a 12v lamp, or a 12v hairdryer – as sold at chandleries (useless, in my experience), a 12v charger for a mobile phone, and anything else which needs 12 volts. The centre contact is positive, and the ‘skirt’ is negative. They may have their own fuse in the central fuse board.