The chart is very much in the style of other charts produced by Jeffreys at the time and indeed this chart adjoins with the northern boarder of Jeffreys' chart 'The Island of Cuba with part of the Bahama Banks and the Martyrs' (see Heritage Charts A504). This is a later, 1794, edition of the chart published in London by Laurie & Whittle.
Jefferys includes on the chart a great deal of hydrographical information around the Florida Peninsular and the Islands of the Bahamas. This includes soundings and channels. He also marks sandbanks, reefs currents, anchorages and includes 'rhumb' or 'loxodromic' lines [1]. Such lines were only really useful in waters which were bounded by not too distant land fall as they did not take account of the curvature of the earth.
The inclusion of ships to illustrate the passage through the New Bahama Channel not only decorates the chart but it also highlights the economic importance of the area at the time. Jeffreys includes some cartographic detail on the mainland Florida Peninsula which includes land relief shown pictorially, rivers, lakes and fresh water sources. Interestingly enough he includes no settlements, towns or ports other than that of St. Augustine on the north east coast.
Overall, the chart does everything one would want as an arm-chair sailor back in London. It is informative, artistic and historical, but one wouldn't, necessarily, want to navigate by it.
[1]. Taken from an initial bearing it is a line on a sphere that cuts all meridians at the same angle. It is the path taken by a ship that maintains a constant compass direction.
This chart of the New Bahama Channel and the Bahama Islands was originally produced in 1775 for inclusion in Thomas Jeffereys' atlas; 'The West-India atlas: or, a compendious description of the West-Indies'. It's full title reads; 'The Peninsula and Gulf of Florida or New Bahama Channel with the Bahama Islands'.