An investigation has been launched to find a mystery object which caused a fishing boat to start sinking in the Cromarty Firth.
The lone fisherman on the 23-foot Challenger boat from Cromarty issued a Mayday call on Saturday after the vessel hit an unidentified object and began taking on water.
The incident happened about half-a-mile from shore, one mile east of Cromarty Harbour, and led to a rescue involving the Invergordon RNLI lifeboat team, Coastguard helicopter, local fisherman and the recently reinstated Cromarty-Nigg ferry.
The lifeboat crew has passed on the co-ordinates of the mysterious hazard to the Port of Cromarty Firth authority, which is now attempting to establish what caused the incident.
A spokeswoman for the port authority said: “We can confirm the port authority was informed of a potential new navigational hazard in the Cromarty Firth on Saturday.
“The uncharted object lies in an area of shallow water and efforts are ongoing to establish its exact nature.
“In the interests of safe navigation, a navigational warning has been issued and a temporary buoy has been established.”
Michael MacDonald, a member of the Invergordon lifeboat team, said he had not been aware of a problem in the area in the past.
“It is something that will have to be investigated and looked at more closely,” he said.
“It was a strange one. It could be an old anchor, a rock or something. I’ve been on the boat for nine to 10 years, and I’ve not heard of anything in that area.
“We got the location of where it happened and we’ve passed that onto the port.”
The vessel was secured alongside the lifeboat and towed to the safety of Invergordon’s West Harbour.
The incident happened just two hours after pranksters set-off two flares from Cromarty Harbour at about 7am, triggering an emergency response.
The culprits were branded “idiots” by local community leaders, who said there could have been a tragedy if the flares had disrupted a genuine exercise.