The chart depicts the track of H.M.S. Jupiter passing Madagascar in the year 1807. As the chart states:

'The track of His Majesty's Ship Jupiter Commodore Baker in 1807 having under his Convoy eleven Indiamen who being prevented going to the north by constant Northerly Winds on getting the SE Trade carried the Fleet thro' this passage without meeting any Island or Shaol'

As is stated above she was acting as escort for eleven East Indiamen. The continuing war with France had left many of the convoys to India, the East Indies, and China vulnerable to attack by French ships. As a reaction to this threat the British began to sail in convoy and, as here, with a military escort.

H.M.S. Jupiter was a 50 gun fourth rate ship-of-the-line launched in 1778. She was wrecked on the 10th December 1808 - just three months after her return from the East - when she struck a sunken rock in Vigo Bay.

The chart also bears the track of the East Indiaman Surrey dated 1805.