On 18 July 1949 USS Cochino put to sea for a cruise to Britain, and Arctic operations. Her group ran through a violent polar gale off Norway, and the joltings received by Cochino played their part in causing an electrical fire and battery explosion, followed by the generation of deadly hydrogen [chlorine] on 25 August. Defying the most unfavorable possible weather conditions, men of Cochino and USS Tusk (SS 426) fought to save the submarine for 14 hours, performing acts of skillful seamanship and high courage.

A second battery explosion on 26 August made "Abandon Ship" the only possible order, and Cochino sank north of Norway in position 71.35N. 23.35E. All Cochino's men were rescued by the valiant Tusk who had lost seven of her own men in the attempt to save Cochino.