The Nore is a sandbank at the mouth of the Thames. It is marked by various buoys and a lightship with a revolving light. This ship lies about three miles from the nearest point on the Kent coast and about the same distance from the Essex coast. It is about 47 miles below London Bridge. The first light was placed there as an experiment by Mr Hamblin in 1731. Trinity House established its first vessel there in 1793.

Wyllie described the Nore light vessel in his book 'London to the Nore' (1905), pp. 165-66. ‘Her mast stands in the middle of the ship, surmounted by a red ball and a big lantern, with the machinery for the revolving light built round the mast. At night this is hove up to the hounds. A wonderful ray it sends quivering round the horizon, lighting up for a moment the passing ships, which appear like ghosts and vanish.A horn is sounded in foggy weather, and a gun is fired when vessels are seen to be standing into danger.’ The present sketch is probably one on which a more finished version, PAE1667, is based.