The largest wellboat in Scottish aquaculture was a noticeable visitor to the Firth of Clyde as it passed Largs on Tuesday.

The Ronja Star stood out on the Firth of Clyde, dwarfing the CalMac ferry beside it, as walkers on Largs Promenade wondered the origins of the ship

 It is a fish carrier sailing under the flag of Norway, and is the largest wellboat in Scottish aquaculture, being officially welcomed to salmon farmer Bakkafrost Scotland’s fleet in 2022.

The 87-metre long hybrid-power vessel, commissioned from the world’s biggest wellboat operator Sølvtrans in Norway, is equipped with an mechanical sea lice removal system, and a reverse osmosis system to produce fresh water from sea water for freshwater treatment. This provides dual treatments for gill health and sea lice in one operation.

Star spotting: CalMac ferry looked tiny in comparisonStar spotting: CalMac ferry looked tiny in comparison (Image: Newsquest)

It has a well capacity of 4,000 m³, and is permanently stationed in Scotland.

The company said the Ronja Star had been built to handle fish with care, while increasing biosecurity in line with its sustainability aims, which will see a rise in the use of freshwater treatments across its marine sites on the west coast of Scotland.

The vessel has state of the art life support systems, which includes high-capacity oxygen production, a carbon dioxide removal system, and a water-cooling system to ensure the fish are kept in optimal condition during treatment.

In addition, it has an automatic cleaning system, alongside sensors and cameras to monitor fish and water quality.

The Ronja Star is fitted with diesel electric propulsion and a battery hybrid solution which reduces fuel consumption and emissions, all while generating less noise.

Wellboats are described as a unique kind of fishing and housing facility vessels. These types of boats provide invaluable assistance to the entire fisheries sector both in terms of commercial viability and the end-consumers’ satisfaction.