ships lost from maine

i have been looking for info on a ship that was lost from maine in the revoultion from bath maine i have old family letters that state William Mitchell was lost at sea with manny other me from bath  when washington called fro more troups poss was a storm acording to letter i belive about 1780 letter said many other men from bath were lost when this ship was lost thought there would be someone else who lost a great great grandfather on this ship as well  any ifo would be most helpful