Cook has begun career of the seaman by the simple ship's boy on the trading brig-coal miner of "Frilav" belonging to ship-owners John and Henry Walkers, on a route London — Newcastle. In two years has been translated to Walker's other ship — «Three brothers».In three years, in 1755, Walkers have suggested it to accept command over "Frendship", however Cook has refused. Instead on June, 17th, 1755 it has registered the sailor in Royal navy fleet and later 8 days was given assignment on the 60-gun ship of "Needles". This fact in its biography results in bewilderment of some researchers — the reasons on which Cook has preferred heavy sailor's work of a captain's post in merchant marine fleet are unknown. But in a month after arrival Cook becomes the boatswain.On reaching a two-year experience, in 1757, James Cook successfully withstands examination on the master (English Sailing Master), and on October 27 is given assignment on the ship "Solebey" under command of captain Craig. Cook was at this time twenty nine years old. From the beginning of Seven-year war it is assigned to the 60-gun ship "Pembrok". "Pembrok" participated in blockade of the Bay of Biscay, then in February, 1758 was sent to the North American coast (Canada).