Out in the open blue water, researchers capture on video a fin whale swimming off Croatia's Adriatic coastline.
Whales are known to visit these waters in the spring and summer months following swarms of krill - tiny shrimp-like crustaceans that whales feed on.
Sightings have also been reported this year off the coasts of Montenegro and Albania further south.
Marine biologists from the Blue World Institute, a conservationist and research organisation, filmed the 15 meter whale swimming in the Velebit Channel, a narrow body of water separating the coastline and nearby islands, near the coastal town of Starigrad.
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