VESSEL REVIEW | Maelstrom – New shallow-draught workboat for French mussel farmer

French aluminium boatbuilder Chantier Naval Delavergne has delivered Maelstrom, a mussel-farming workboat for Charente-Maritime operator Fabien Chupeau, following the vessel's launch at the commercial port of Les Sables-d'Olonne on October 2, 2025.

Delavergne, which is based at Avrillé in the Vendée, reportedly completed construction in five months.

Maelstrom replaces an earlier Delavergne-built unit ordered by Chupeau's father, making the new vessel a second-generation purchase from the same yard for the same family business.

Chupeau farms mussels in the Pertuis Breton, the strait between the Île de Ré and the Vendée coast. His operation combines mussel concessions, in which mussels are grown on wooden stakes driven into the intertidal seabed, with longlines set in deeper water. The vessel therefore has to work in two quite different environments within a single tide cycle: over shallow stake fields that dry at low water, and over suspended culture in open water where seakeeping matters more.

Design optimised for operation during low tide

Maelstrom has an overall length of 25.36 metres (83.2 feet) and a beam of 6.8 metres (22 feet). The vessel's design draught is 60 centimetres (two feet), a key operating parameter. A hull of this length drawing only 60 centimetres allows the crew to bring the boat directly alongside mussel lines on the flood and to remain working over the stakes for as long as possible before the ebb forces a retreat to deeper water.

The hull is aluminium throughout, and is described as a new-generation "rostre" (“rostrum”) form, a bow configuration intended to improve seakeeping. Defining characteristics include the rostre hull for behaviour in a seaway, large cargo capacity beneath the crane, and a hull form adapted to the mussel environment. The last point refers to the geometry needed to lie close to stake rows without fouling them and to sit safely on or near the bottom as the water drains away.

Built to maximise capacity even with multiple round trips

The emphasis on capacity beneath the crane reflects how these boats are used. Mussels are lifted from stakes or longlines by crane and deposited on deck or into containers, so the useful deck area is the area the crane can reach with a full load. The design brief prioritised this working footprint over accommodation or enclosed volume, which is consistent with a vessel that returns to port every tide rather than staying at sea.

The electronics suite includes a Furuno radar.