As part of conservation means, ecotourism on shark watching activities has been popular for the last 10-25 years. Achieving rank fourth in the shark tourism world, shark watching tourism in Indonesia begins to play as an economically important for gross national products (GDPs). Morotai, as one of the prominent shark diving and shark research site in Indonesia is became popular in recent years. However, the precise number of blacktip reef shark living in Morotai's most famous dive site, blacktip point is unknown. The knowledge of shark individual marking and their number is important for developing ecological assessment, shark diving carrying capacity, and shark behavior observation. DOV (Diver Operated Video) is employed to visually identify the blacktip reef shark's fin marking, its patterns and its changes over time. Analysis of hundreds of photographs and video of the Carcharhinus melanopterus during SCUBA diving-from February 2015 to March 2019-reveals the precise number of these blacktip reef shark living in the proximity of blacktip point area. Study also shows that the photo identification shark fin's natural marking can be used effectively to recognize unique individual of blacktip reef shark.