It occupies an extent of forty-five miles, and is fronted by extensive reefs, which project for twenty-three miles; the north extremity of the shoal water is twenty-six miles, nearly due west from Cape Pearce.

It terminates with a narrow point, and then trends in to the South-West towards the coast.
The Medusa Bank fronts the entrance of Cambridge Gulf; it projects from the coast, near Cape Domett, to the North-West for seventeen miles, and terminates with a narrow spit, thirteen miles north from Lacrosse Island, in latitude 14 degrees 30 1/2 minutes.

Both these banks are of sand, and their edges are very steep to.

They are covered with large quantities of mollusca, which are also abundant in the sea in their vicinity.
CAMBRIDGE GULF extends from Lacrosse Island in a South-South-Westerly direction for sixty-four miles.

The entrance, between Cape Domett and Cape Dussejour, is twelve miles wide; but Lacrosse Island, under which there is good anchorage for vessels going in or out of the gulf, divides the entrance into two channels.