Accounts for the company filed at Companies House show Streamline made £2.9 million pre-tax profit in the year ended 31 December 2013 compared with £614,000 in the preceding year.
Turnover increased by about 40 per cent, £10.9m, to £36.9m, from £26m last time.
Streamline, which says it specialises in shipping freight to the Northern Isles, has capitalised on moves by oil and gas majors to develop giant fields West of Shetland, like Clair Ridge.
In August managing director Gareth Crichton said it had recorded a big increase in demand in connection with the new gas terminal that is being built on Shetland to handle output from the Laggan and Tormore fields that Total is bringing on stream.
In the latest accounts, directors of the privately-owned group said prospects for the markets it operates in continue to be encouraging.
They wrote: "The group has expanded its projects department to take advantage of a number of oil-related and energy related developments."
They added: "The group's container shipping service to Shetland and Orkney will suffer the withdrawal of Scottish Government grant support.
"The Government has indicated that the PSO (public service obligation) contract will not be re-let, and the directors are engaged in assessing how to manage this business."
In May 2012 the Scottish Government awarded a £243m contract to run lifeline ferry services to the Northern Isles to Serco.