US companies Tidewater and GulfMark Offshore are creating the world’s largest offshore support vessel owner in a merger deal that values the new entity at around $1.25 billion, writes Eoin O'Cinneide.

The all-stock combination will also see the enlarged player, to retain the Tidewater name, boast the second-highest value fleet in the industry.

Under the deal, which has been agreed by both sets of boards, GulfMark stockholders will receive 1.1