Marbled Mola

Coming back from our morning dives on Sunday with lobsters in the live well and a newly certified diver, I spotted the tell tail sign of a Mola Mola, the lazy tail flap mimicking what’s often confused to be a shark fin breaking the surface. Made a slow approach without frightening it off and everyone got a good look, it stuck around and seemed comfortable enough that I threw my wetsuit on, got my camera and jumped in to get a better look at the big lad or lady.

Mola Mola's find their way into Boston Harbor on the warm summer currents. This friendly "marbled" looking mola was spotted in Broad Sound outside of Deer Island on July 26, 2026. They are slow, awkward swimmers that are most commonly seen "sun-bathing" at the surface. Though some species can get up to 6,000lbs/2700kg, they're harmless and feed on primarily jellyfish as adults, assisted by a mucus-type lining in their digestive tract that prevents them from getting stung. They're timid and shy with divers but won't always immediately flee, however when they do want to get away they can move fast for short periods and in bursts, clocked in with a top speed of 2mph/3.2km which at 1.7kt is faster than most swimmers could keep up. If you see one in a boat approach slowly and quietly to avoid scaring them away and observe for a short period without touching or harassing them especially since they are listed as Vulnerable by the IUCN (International Union for the Conservation of Nature).