A fishing boat had to be towed to safety after becoming grounded at the entrance to Scalloway Harbour because of a faulty buoy.
The Buckie-registered Vela got into difficulty at around 6.30pm on Thursday when she sailed too close to the NAFC marine centre at low tide.
The Sumburgh-based search and rescue helicopter was called to the scene and the Aith lifeboat was launched.
Vela’s trawling partner, Nordfjorder, was able to get a line to the 24-metre vessel and pulled her back alongside. However they had to wait until shortly before midnight to allow the water levels to rise.
The helicopter was stood down when the crew learned there were no casualties onboard the vessel.
Meanwhile the Lerwick lifeboat towed the Banff-registered Aquarius to safety after she suffered problems with her gearbox as she tried to reach the fishmarket.