The Lerwick lifeboat was called out last night to assist a cargo ship that had suffered an engine failure.
Shetland Coastguard received the call at 8.55pm from crew of the Norwegian vessel the Gripfisk.
A tug boat was not available and the lifeboat was launched at 9.20pm.
The Gripfisk was taken close to Lerwick harbour where a tug took over the rest of the journey.
The Gripfisk arrived in Lerwick at about 3.30am.