French water treatment specialist BIO-UV Group has supplied its BIO-SEA ballast water treatment system (BWTS) to French shipbuilder Chantiers de l’Atlantique for operation on board the first in a series of Accor-operated luxury sailing yachts.
Factory acceptance trials (FAT) for the chemical-free BIO-SEA B01-0135 unit was successfully completed, with installation on board the first Orient Express Sailing Yachts vessel taking place at the St Nazaire shipyard.
The vessel was floated out on 16th June, 2025.
When the yacht becomes operational next year, the UV-based BIO-SEA system will be treating water flow rates up to 135 cu m per hour. A sister vessel, scheduled for delivery in 2027 will also be fitted with a similar B-type BIO-SEA BWTS.
At 220 m in length and with gross tonnage of 26,200, ‘Orient Express’ will be the world’s largest contemporary sailing yacht and the first to deploy the shipbuilder’s in-house designed SolidSail wind sail system.
This features three 100 m tall lightweight masts each of which will be rigged with 1,500 sq m Solid Sail/AeolDrive rigid but foldable sails.
Commenting on the significance of the order, Maxime Dedeurwaerder, BIO-UV Group’s Sales Director for Solutions, explained; “Our ballast water treatment systems resonate with environmentally conscientious shipowners and builders because of the compact, low energy consuming reactor technology we have developed.
“The BIO-SEA ‘B’ unit for the Accor ships, for instance, needs only one UV reactor, optimising space and energy saving efficiency without any impact on ballast water treatment performance to limit invasive species proliferation,” he said.
Arnaud Le Joncour, Senior Vice President Sales and Marketing at Chantiers de l’Atlantique, added: “Chantiers de l’Atlantique has good experience with BIO-UV Group’s BIO-SEA ballast water treatment systems, with more than 20 installations over the past decade or so.
“The BIO-SEA technology combines mechanical filtration and UV disinfection providing chemical-free treatment compliant with both IMO and USCG regulations, which was an important consideration for the operational scope of the Accor sailing yachts,” he said.
With treatment capacities ranging from 100 to 500 cu m per hour, the BIO-SEA B Series automatically regulates the UV dose according to the water quality.
Treatment performance is not affected by water temperature or salinity and since no chemicals or active substances are used in the treatment process, deballasting can be carried out without detriment to the marine environment.
A BIO-SEA BWTS can also benefit from the French water treatment specialist ‘warranty for life’ policy, which assures ship operators of the through-life robustness, reliability, and performance of their installations.
Valid with a three or five-year aftermarket service agreement, the warranty is contingent on a BIO-SEA system being installed and operated in full compliance with the operation and maintenance manual; that servicing is undertaken by a certified BIO-UV technician; and that any replacement parts or consumables are supplied directly from BIO-UV Group or its official network.

