The Loughs Agency have said efforts to salvage its catamaran from the River Foyle are continuing.
It is now almost a month since MMV Ostrea sank beneath the River Foyle.
The vessel had been docked at the Foyle Marina.
A spokeswoman for the Loughs Agency said: “Loughs Agency are working with our insurance company who have appointed a salvage company who are co-ordinating the recovery of the MMV Ostrea.”
The MMV Ostrea was being used to operate a multi-disciplinary scientific monitoring programme within Lough Foyle.
The vessel, which is insured for £1.8m, was equipped with both biological and geophysical survey equipment specifically for use in fisheries assessments, such as regular sampling campaigns for shellfish hygiene, on behalf of the Food Standards Agency in NI and the Food Safety Authority of Ireland.