Windcat, which operates crew transport services, has ordered two, hydrogen-powered vessels.
The comissioning service operating vessel (CSOV) order brings the company's fleet to five with an option on a sixth ship.
"CMB.TECH's dual-fuel hydrogen technology will be implemented aiming to minimise the CO₂ footprint of offshore energy production and vessel operations," Windcat said in a statement posted on its website.
The first three ships, which are being built in Vietnam, will be delivered in 2025.
The hydrogen-powered CSOV series was announced by the company last year and is a collaboration between Windcat and Damen Shipyards.
The company secured a hydrogen bunkering licence for the ports of IJmuiden and Amsterdam in August 2022.