Maritime Craft Services (MCS), which is based at Largs Yacht Haven, has been providing support craft including tug boats, crew launches and crane barges since 1977. It operates throughout Europe, the Middle East, India and Africa.
The new funding, provided by Clydesdale Bank, will allow the family-run firm to add four vessels and grow its offshore wind farm services. MCS's Dutch-born managing director and former sea captain Dirk Kuyt said: "The expansion of our fleet is an integral part of our strategy to grow the company by entering new markets and, in particular, the offshore wind farm sector."
The company, which employs more than 110 staff, including 65 seafarers, is expected to increase its turnover to 13m next year.
Clydesdale Bank is providing the financing through its "Investing for Growth" initiative.