Sailed on a whaling venture from London to the coast of Brazil (September 1776). Midshipman on the British vessel, the Belle Isle (July 1777).
Obtained his discharge, and went to Dunkirk, where he offered his services to the American cause. Sailed from Dunkirk on another whaling venture (1777-78), and provided the American commissioners with an account of the British whaling fleet (October 1778).
John Adams recommended him for a position aboard the General Mifflin with Captain McNeil.
Native of Newport, Rhode Island. Brother of William Grinnell, first lieutenant on the Columbus.