The first sightings of basking sharks this year off the west coast, have been reported by a tour company which runs wildlife boat trips out of Oban.

Basking sharks are the second largest fish in the world and cruise in Scottish waters each summer, growing up to 10m (33ft) long. Despite looking fearsome and a little like the great white shark with a massive jaw one metre wide, they are harmless and exist by filtering out plankton from the sea water it takes in through its gills.

Tour company Basking Shark Scotland said that following up reports from local fishermen of the basking arriving around the Inner Hebrides they went looking for them.

"Passing numerous minke whales and a pod of over 100 strong common dolphins they searched around the islands of the Inner Hebrides and found a small aggregation of basking sharks. Four individuals were sighted, the largest at least eight metres and male."

They are found in temperate seas across the world, but normally arrive in UK waters in the spring, with many having completed a large offshore migration over winter.

Basking Shark Scotland owner and marine biologist, Shane Wasik said "It was really exciting to see the basking sharks back in our waters, and great to have some large individuals. They undertake such huge migrations, it's such a privilege to see them every summer. We're looking forward to the shark season ahead and pushing on with our work with them."

According to Scottish Natural Heritage "In Scottish waters, basking sharks are seen most commonly off western coasts, and especially around the outer Firth of Clyde. Recent studies funded by SNH , collating data collected by the Wildlife Trusts, have confirmed two other hotspots for basking sharks: in Gunna Sound, between Coll and Tiree, and around the rocky islet of Hyskeir, southwest of Canna. Considerable numbers of sharks have been consistently recorded here up to four times the numbers seen elsewhere in the UK."