Jackup drilling rig successfully navigated through Cook Inlet. Foss Maritime Co. tugs Justine Foss and Jeffrey Foss have completed a successful tow of a jackup drilling rig to its winter harbor in Port Graham, Alaska. The Spartan 151 jackup drilling rig was moved from its drill site at Nikiski, in the Cook Inlet, which becomes choked with ice during the winter. Gary Faber, president and COO of Foss Maritime, said the successful tow underscores the company's competence in navigating…