John Fredriksen, Idan Ofer, Emanuele Lauro, Robert Maersk Uggla, Tor Olav Troim and Fred Olsen — they are among the most influential names in shipping today.

Their reputations stretch perhaps further than their fleets. Together, they and their families control assets worth almost $50bn.

Yet they all have a far less glamorous claim to fame. They have all bet heavily on the offshore business.