U.S. Marines depart amphibious assault ship USS Tripoli (LHA 7) by helicopter and transit over the Arabian Sea to board and seize M/V Touska. The Marines rappelled onto the Iranian-flagged vessel, April 20, after guided-missile destroyer USS Spruance (DDG 111) disabled Touska’s propulsion when the commercial ship failed to comply with repeated warnings from U.S. forces over a six-hour period.