'Elisa' is the largest workboat in the Ports of Jersey fleet and will be used commercially alongside the Duchess and the Duke of Normandy.
She has been officially renamed in a ceremony in the Netherlands and will begin working mainly in northern Europe.
The six-year-old vessel will be supporting marine projects as part of the Landfall fleet, which is made up of 13 anchor-handling tugs and multi-purpose workboats.
Donford Nicholas, Head of Marine Services, says he is pleased to see the success of the Marine Services Team in generating income for PoJ.
"As always, any profit from our operating activities off-island is ploughed straight back into the business, as we continue to develop and invest in our services for the benefit of Islanders, visitors, and businesses."
To follow marine custom, a 'Godmother' was given to the vessel, which is a deep-rooted naval tradition said to bring good luck and protection to the boat.
Ellie Cousins, who works for Ports of Jersey, was given the honour and shared a short speech at the ceremony.
Elisa is a Shoalbuster built by Damen, a ship-building company, in 2017 with a deck crane which can lift eight metric tons and a winch that can pull 100 tons.
However, the new vessel is too large to be registered in Jersey so will be registered in Gibraltar instead.
A total of £5 million was allocated by Ports of Jersey for the purchase of Elisa and the marketing of the new boat.
The Duke of Normandy worked 327 days of the year in 2022 and the Duchess 333 days in her first year.
Both were used on a range of projects at some of UK’s largest ports, including Felixstowe, Harwich, Liverpool, Southampton, and on the installation of a gas pipeline in Estonia.