During the morning of 27.8.2017., the Blue World Institute received a report about the observation of two fin whales west of Lošinj. The researchers immediately went to the sea to collect information on this sighting and to determine the condition of the observed animals. The whales were found about 3 NM west of the Mali Lošinj bay. Observed animals were two adult fin whales whose size was estimated at about 17 and 18 meters. One animal had large multiple scars of a serious injury caused by boat propeller. Apart from the healed scar, whales looked healthy. During nearly two hours of observation, the animals were swiming with an average speed of about 3-4 knots traveling south. They were diving for about 10-15 minutes while on the surface they spent on average just about one minute before the next dive. During the survey, researchers collected behavioral data, photo identification photos, and sloughed skin for genetic analysis.