A crewman with an injured hand is currently being airlifted from a French fishing vessel by a coastguard search and rescue helicopter from Shetland.
Reports of the incident were first received at 6.30pm, with the vessel located approximately 45 nautical miles west of Unst.
Rescue 900 from Sumburgh has been sent to the scene to assist the crewman, with transfer on to Tingwall taking place.
A coastguard spokeswoman said: “We received a call to assist in the medical evacuation from a fishing vessel situated north-west of Shetland.
“The French vessel is located 45 nautical miles west of Unst with a crew member sustaining an injured hand.
“Rescue 900 from Sumburgh has been sent to assist, with Lerwick coast rescue team providing assistance at Tingwall to manage the handover to the ambulance service.”