A wrong turn with a faulty satnav has led to a lucky rescue for a stranded dolphin left fighting for its life on a beach in the Highlands.

Lorraine Culloch and her partner Mike Robertson were heading to a familiar spot in the Cromarty Firth to do some dolphin watching when their car's satnav sent them down the wrong road.

Realising their mistake, they continued on the route to Nigg Bay, where they chanced upon young dolphin Spirtle struggling in the shallows.

"We'd been on our way home to Arbroath when we thought we'd pop by one of our favourite spots to see if we could spot some dolphins," says Lorraine, a care home worker.

"We'd been there a million times before but for some odd reason we still went the wrong way."

Instead of the pods of swimming dolphins Lorraine and her fiance of 16 years had hoped to find, they spotted one distressed looking dolphin instead.

Four-year-old Spirtle, whose mother Porridge is one in a big family of dolphins who usually occupy the Moray Firth, was found labouring on the beach on Sunday by the couple.

"I have a powerful camera lens and I could see it lying on the beach," says 38-year-old Lorraine, a keen photographer.

"Mike waded out to see if it was OK but we could tell pretty instantly that it was struggling."

Anxious to help the dolphin, Mike managed to get enough signal to call the police who in turn said they'd contact the Scottish SPCA. As time passed, the couple became anxious no one was arriving.

"The poor thing was splashing about and the seagulls were starting to attack it," says Lorraine.

"We finally managed to get enough internet signal to get the numbers of the SSPCA and the British Divers Marine Life Rescue and call them. Suddenly this army of people showed up."

Shortly after 5.30pm, a team of rescuers gathered to try to help, covering the creature in wet cloth and seaweed in an attempt to keep her wet and cool.

"They were amazing," says Lorraine. "The vet came at midnight and said that the dolphin was healthy enough to deserve a second chance."

The team had to wait until dawn for the tide to return so the rescuers, along with Lorraine and Mike, camped throughout the night to keep watch over the dolphin until the water level was high enough to attempt a rescue.

"They were there without their tea, helping right through the night," says Lorraine.

"We slept in cars and tents until morning and at around 4.30am they waded out into the ice-cold water and managed to get her swimming."

At first, Spirtle was too stiff and tired to swim properly, moving in circles instead until the tide pulled stronger.

"At one point she looked like was going to come back into the beach, which was really worrying, but then she headed straight out," says Lorraine. "It was amazing to see."

According to research at Aberdeen University, there are around 200 different dolphins in the area, with just under half regularly swimming within the confines of the Moray Firth.

Not all rescues are as successful as Spirtle's, however, with several incidents each year on Scotland's coastline where not all animals can be saved.

The British Divers Marine Life Rescue offers guidance if people come across a marine animal in distress.

Trying to return a dolphin or seal to the sea yourself could result in injury either to yourself or to the animal, so you are advised to call the BDMLR or the Scottish SPCA instead.

A BDMLR spokesman said: "Please note the place, the state of the tide and any injuries you can see without getting close.

"Please calls us and we will then advise you on what to do and will get a trained medic out as soon as possible."

"The last report we had was that Spirtle was still swimming strong," says Lorraine.

"We've shared the photos of her rescue on the Scotland from the Roadside photo group and have had a fantastic response from people.

"It's usually all doom and gloom online so I'm glad we could share a story with a happy ending."

If you spot a marine animal in distress you can call the British Divers Marine Life Rescue on 01825 765546 or the Scottish SPCA on 03000 999999.