The Sea1 Diamond support vessel, the first of four 120-meter ships being built by Sea1 Offshore in China, is ready for delivery in January 2027, featuring a marine crane and a helicopter deck. This vessel is part of a larger project to serve the oil and gas industries as well as the renewable energy market.
Details of Ship Construction and Design
Sea1 Offshore placed an order for the construction of the first two support vessels with Cosco Shipping in November 2024. Construction of the Sea1 Diamond began in September 2025 and it was launched in July 2026. The vessel is currently being finalized at the COSCO Nantong shipyard, where a 250-ton crane and helicopter deck have been installed.
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The Huisman crane on the vessel is designed for underwater operations up to a depth of 3000 meters, and the helicopter deck is designed to accommodate Sikorsky S-92 helicopters. This vessel is specifically designed for supporting offshore energy projects and transferring personnel to oil and gas platforms.
Ship Features and Capabilities
The Sea1 Diamond vessel has a cargo deck area of 1400 square meters and will be equipped with a 250-ton crane, two storage areas for remotely operated vehicles (ROVs), and a moonpool. This vessel can accommodate up to 120 personnel and is designed to be compatible with methanol and 100% biofuel.
Sea1 Offshore has announced that this vessel is not yet committed to any specific customer after delivery, and its capabilities are open to attract clients in both the oil and gas and renewable energy sectors. This could bring new financial and commercial opportunities for the company in international markets.
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