Apparently, the only recorded example of the only chart by John Inskip (died 1791), described in records as "mariner", who sailed with John Eastabrooke (died 1804) aboard the London East Indiaman to the East Indies in the late 1780s. The chart was published by William Darton, Sr., (1755-1819), from his very first premises in White Lion Court, which he occupied only briefly between 1787 and 1788. The Darton family of publishers were Quakers, best known for issuing books and games for children.
This very detailed, large-scale chart, oriented with east to the top, shows the strait between the islands of Bangka and Belitung in the north Java Sea which, in turn, lie between Sumatra and Borneo. A route is plotted with numerous depth soundings navigating around the "Treacherous islands" that fill the channel. The "References" specify that "It will be necessary to have a Boat on each Bow Sounding".