A close relative to the manatee, dugongs are thought by some to be the motivation of seafaring tales of mermaids with their shapely bodies and fluked tails. In fact, they belong to the classification order Sirenia. Dugongs are the only strictly herbivorous marine mammals in the world and can be found all throughout the southern hemisphere, encompassing 40 countries and territories within the Indian and Pacific Oceans.

These gentle giants can grow up to 13 feet long and spend day and night grazing underwater grass. Because they are slow swimmers and prefer to stay in shallower waters, dugongs are relatively easy to encounter while scuba diving. However, after centuries of over-hunting for their meat, oil, skin, and bones, they are vulnerable to extinction. Numbers struggle to rebound, even after making them a legally protected species within most of their range. If you want to dive with dugongs, explore the map below to see all the best dive spots where they live.