The U.S. M/V Ocean Trader Maritime Special Support Base Vessel, formerly known as cragside, was a large RoRo vessel built by Odense Steele Shipyard for Maersk Line. The captain is 193 meters long, 26 meters wide, has a draft of 5.6 meters, has a displacement of 20,980 tons, and has a maximum speed of 14.2 knots (about 26.3 km / h). Kragside laid the keel in 2010 and was completed and delivered in 2011. In November 2013, the U.S. Navy awarded Maersk a $73 million contract to convert it into a large maritime special operations support mothership (BSSOM) and renaming it USS Ocean Trader.
The Ocean Trader can carry a special operations detachment of 209 personnel and accommodate all the equipment needed for its operations, such as helicopters, weapons and ammunition, underwater thrusters, high-speed speed boats, food and water, etc., to achieve self-sufficiency and mobile deployment. The ship has an endurance of at least 8,000 nautical miles, a self-sustaining force of more than 45 days and nights, a crew of only 50 people, and can operate normally in harsh sea conditions with 50 knots of high winds and 20 feet of huge waves. The ship is equipped with conference rooms, communication rooms, medical rooms, activity rooms, aviation maintenance support rooms, equipment rooms, weapons and ammunition rooms, operation command centers, ship release and recovery centers and other departments, in addition to equipped with forward-looking infrared systems, diving support systems, etc., and reserved installation positions for small-caliber naval guns, which can be called a floating special operations base. Due to the low speed of commercial ships and the inability to meet the needs of rapid response in special operations, the U.S. Navy upgraded the power system of the "Ocean Trader", which was led by BAE Systems and initially completed the transformation in 2016. At present, the ship's speed has been increased to 21 knots (about 38.9 km / h), an increase of nearly 50%, the ship's flight deck can accommodate two MH-60 helicopters (or 1 CH-53E) at the same time, its size meets the U.S. Navy's active service of all types of helicopters take-off and landing requirements, the Army's MH-6 small helicopter, AH-64 gunship, OH-58 reconnaissance helicopter, CH-47 transport helicopter and V-22 tiltrotor can also take off and land. The ship's hangar can accommodate 2 MH-60 helicopters. When using drones, the deck can take off and land 4 medium-sized multi-rotor drones at the same time. The stern-mounted boat release and recovery center can carry inflatable rubber boats, rigid inflatable boats, high-speed motor boats, etc., and can carry up to 4 boats.
Two helicopter hangars were added to the front of the bridge, and the open deck at the front was converted into a helicopter landing deck, without a landing aid system, which can support 2 MH-60s at the same time or 1 MH-53 to take off and land in level 5 sea conditions, and have the ability to use drones. The ship is also equipped with a small boat garage, which can accommodate 8 12.5x3 meter boats, 1 10 meter boat, 4 motor boats and 4 Zodiac F470 RHIB (hard-shell inflatable boats), and there are also 4 booms on the ship, the lifting weight reaches 13.6 tons, and the lifting operation of the small boat can be carried out at a maximum speed of 10 knots.
Suitable for overseas special operations support missions, the ship is part of the U.S. Navy's MSC (Military Maritime Command), but is actually under the command of the U.S. Special Operations Command. Canada and the United Kingdom also plan to build their own versions.