NRP Almirante Gago Coutinho (A523) is a Portuguese Navy survey vessel, originally built as the USNS Assurance (T-AGOS-5) of the United States Navy. The vessel belongs to the Dom Carlos I-class, which are adapted from the US Stalwart-class ocean surveillance ships designed primarily for hydrographic and oceanographic surveys. The ship measures approximately 224 feet (68 meters) in overall length, with a waterline length of about 203 feet 6 inches (62.03 meters). Its beam spans 43 feet (13 meters), and it has a draft of 15 feet (4.6 meters). Displacement figures are around 1,600 tonnes at light load and up to 2,301 tonnes at full load. The vessel’s hull design resembles that of Powhatan-class tugboats, emphasizing its robust construction suited for extended ocean operations. Powered by a diesel-electric system, the ship features four Caterpillar D-398 diesel generators and two General Electric electric motors, producing a combined 3,200 horsepower that drive two shafts. This configuration enables the vessel to reach a maximum speed of 11 knots (20 km/h), with an operational endurance of thirty days and a range of approximately 3,000 miles (4,800 km). Its gross register tonnage is 1,584, and it has a deadweight tonnage of 786 tons. The crew complement varies between 32 and 47 personnel. Originally designed for Cold War anti-submarine warfare support, the USNS Assurance was equipped with the Surveillance Towed Array Sensor System (SURTASS), enabling underwater acoustical data collection. This capability was crucial during its service in the US Navy. In 1999, the vessel was transferred to Portugal, where it was commissioned as NRP Almirante Gago Coutinho, continuing its mission as a hydrographic and oceanographic survey ship. Its conversion and transfer marked its significance in expanding Portugal’s maritime research and survey capabilities.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.