The Mercenary Sea Volume 1

Action and adventure set in 1938! The South Seas. Japan has invaded China.
War in Europe is imminent. Ex-bootlegger Jack Harper captains the
Venture, a refitted German U-Boat, with a crew of expats, mercenaries, and
treasure hunters. They do whatever it takes to stay afloat, often running up
against pirates, headhunters, and spies. Jack is always one step away from the
greatest score of their lives: finding the legendary lost island of Koji
Ra.
This trade paperback collects issues #1-6 of the critically acclaimed
series, as Jack and the crew of the submarine Venture take a job offered
by a shady American operative: rescue a British agent trapped behind enemy lines
who has valuable information about the Japanese war effort.