Probably George and James Coleman, Eliza's older brothers.

(for George see A27n5 ; for James, S26n6 ).

But one of the two might have been their younger brother John Brown Coleman Jr., aged ca. 15 (b. 1800). According to Martin(1957, p. 315, note), John Brown Coleman Jr.

" . . . afterwards went to Nantucket and by 1842 was Master of a whaling-ship hunting in the Pacific. At Tahiti he signed on a deserter who had been ill-treated on another vessel. This seamen was Herman Melville, famous later for his story of 'Moby Dick'. It is said that the vivid descriptions of whale-hunting in Melville's several books largely resulted from his training under Dartmouth-born Captain Coleman."
In his two volume The Melville Log (1951, p. xxiv), Jay Leydahas the following biographical note:
"JOHN BROWN COLEMAN, Jr (1800-?) The third, last & most impressive of the three whaling captains under whom M served, Coleman hired M at Eimeo as harpooneer, on the Charles & Henry, from Nov 1842 through April 1843. A document that tells much of Co1eman's character & the ship's whaling voyage before M signed on her is Coleman's letter of 2 Nov 1842 to his owners, the Coffins. M's impressions of Coleman may be found in his portraits of the captains of the 'Leviathan' & 'Arcturus' (in Omoo & Mardi). In the Friends' Records, Nantucket, Wilson Heflin has found that Coleman was born in Nova Scotia, of a Nantucket Quaker family, & that he married Susan Coffin."
On p.154 of the same book, Leyda edits a passage from Omoo to show that Coleman is the original for the Leviathan captain and that the Charles and Henry is the original for that whaling vessel:
"Now, if her crew were to be credited, the [Charles and Henry] was not the craft to our mind. But I had seen the captain [Coleman], and liked him. He was an uncommonly tall, robust, fine-looking man, in the prime of life. There was a deep crimson spot in the middle of each sunburnt cheek, doubtless the effect of his sea- potations. He was a Vineyarder . . . "We became acquainted with the third mate, a Prussian, and an old merchant- seaman . . . The account he gave us of the ship agreed with my own surmises. A cosier old craft never floated; and the captain was the finest man in the world . . . The only bad trait about the vessel was this: she had been launched under a baleful star; and so was a luckless ship in the fishery. She dropped her boats into the brine often enough, and they frequently got fast to the whales; but lance and harpoon almost invariably 'drew' when darted by the men of the [Charles and Henry]." (Omoo, lxxxii)