Mainprize Offshore

The story of Mainprize Offshore begins not with venture capital, but with a 350-year fishing heritage. In 1979, Bob and Sharon Mainprize established Mainprize Trawling Co Ltd in Scarborough, UK, operating a single fishing vessel in the North Sea. This foundation in the demanding maritime world set the stage for a significant pivot. As the North Sea landscape evolved with the rise of oil, gas, and eventually, renewable energy, Mainprize Offshore saw an opportunity to diversify. The company transitioned from fishing to providing support vessels for these new industries, offering services like seabed surveys, cable guarding, and equipment transfers. This strategic shift was the playbook's first major turn, leveraging deep maritime experience to enter a growing, adjacent market. The real catalyst for growth, however, was the boom in offshore wind farms. A key turning point came in 2024 when private equity firm Alcuin Capital Partners made a significant investment, initiating a partial sale of the company. This wasn't a sale to exit, but a partnership to accelerate. Bob and Sharon Mainprize remained at the helm to continue operating and growing the business they founded. The deal provided the capital to expand the fleet and solidify their position. This was followed by a €25 million financing facility from Siemens Financial Services to fund the acquisition of new, state-of-the-art Crew Transfer Vessels (CTVs). These vessels, based on Mainprize's own proprietary designs, give them a competitive edge, allowing operation in challenging sea conditions where others cannot. Today, Mainprize Offshore is a key European player supporting major offshore wind developers, a testament to a multi-generational ability to navigate changing tides.