The San Martin, a single-screw cargo steamer of 3050 tons, was on her way from Realejo to Tahiti. Built on the Clyde twenty years back, this Peruvian-owned tramp was no longer in her prime.

Since passing out of the hands of her British owners, neglect had lessened her speed, while the addition of various deck-houses, to suit the requirements of the South American firm under whose house-flag she sailed, had not increased her steadiness. 

Captain Antonio Perez, who was in command, was a short, thick-set man of almost pure Spanish descent, swarthy, greasy, and vain—combining all the characteristics, good, bad, and indifferent, of the South American skipper. As part owner of the San Martin he was glad of the opportunity of adding to the vessel's earnings, so he had willingly agreed to take five passengers as far as Tahiti. 

The five passengers were Mr. McKay, his son Andrew, Terence Donaghue, Fanshaw Ellerton, and Quexo; but before relating the circumstances in which they found themselves on board the San Martin, it will be necessary to introduce them to our readers.