The Seigrunn, due for delivery in 2023, will have a capacity of 8,000m³. Illustration: Salt Ship Design.

Seigrunn joins the queue to be world’s biggest wellboat

When the Frøy Rederi wellboat Gåsø Høvding enters service imminently it will unseat the Ronja Storm as the world’s biggest operating wellboat, as its capacity of 7,500m³ is 50m³ more than that of the Sølvtrans vessel.

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But even before the Gåsø Høvding starts work, construction is progressing in Turkey on another vessel with an even larger capacity of 8,000m³ that will take the biggest wellboat crown in 2023.

The 110-metre-long Seigrunn is being built for wellboat company Seistar, based in in Torangsvåg in Austevoll, Norway and has been designed by Salt Ship Design.

Smolt boat

Seistar is also having a smaller, 2,200m³-capacity wellboat, the Seifjell, built specifically for the transfer of smolts.

Both vessels are under construction at the Cemre Marin Endustri yard in Turkey.

Tore Bakke: "No hiccups in the construction so far."

Tore Bakke, one of four brothers who run Seistar, told Fish Farming Expert’s Norwegian sister site,, that the vessels have several new and interesting design solutions.

“Both vessels are designed with circular fish tanks,” said Bakke.

Gentle handling

Salt Ship Design and Seistar have collaborated for a long time to develop the wellboat designs based on gentle and efficient fish handling in combination with a strong focus on hygiene, the environment and quality.

According to Bakke, the construction of the vessels is going according to plan.

“There have been no hiccups in the construction so far, and the first vessel, Seifjell, will be handed over from the yard in September / October 2022 and Seigrunn will be handed over in April / May 2023,” he further said.


The 69.9-metre-long Seifjell is new build 76 from the yard and has two round tanks.

“It is built as a pure smolt / post-smolt boat and is diesel-electric with a battery pack. It has sorting and counting, as well as a newly developed washing system for reusing washing water. It also has zero discharge on the washing water,” explained Bakke.

The 24.6-metre-wide Seigrunn is build-number 77 and will have three round fish tanks.

Treatment vessel

“It is being built as a treatment vessel, with RO (reverse osmosis) and RSW (refrigerated sea water) facilities. It has 600 pipes as fish-carrying pipes to get better fish handling but has all the areas of use that a wellboat has today, and it will be rigged for future treatment equipment,” said Bakke.

Like the Seifjell, the larger vessel will have reuse of water and zero discharge of washing water. It will also have 4,000m³ of freshwater storage and is diesel-electric with a battery pack. 

Seistar AS currently has a fleet of three wellboats and three harvest boats. The newbuilds add extra tonnage to cover increasing demand for treatment services and transport services, especially related to the trend for larger post-smolt in western Norway.