"Did you see that?"
"Holy crap! It dove right out of the water!" yells the captain.
White sharks are known to breach the water, according to the conservancy. "It opened it's mouth right at my feet!"
Sharks are about to get their biggest big screen make-over since Steven Spielberg's Jaws came to the screens 43 years ago.
But as he looks around for sharks a great white rises from the water, right underneath the platform with its jaws open before diving back under.
Over in the States, they generally drop the "great" and just call them "white sharks".
As Dr Skomal, of the Massachusetts Division of Marine Fisheries (DMF), explains: "For the first time, modern scientists have predictable access to white sharks in the North Atlantic and the ability to study their life history and ecology over multiple spatial and temporal scales".
Researchers have tagged eight sharks off the Cape so far this season and have been urging beachgoers to be "shark smart" and use the conservancy's free app that provides information on white shark sightings and movements. While encounters like this one are rare, this video shows that they're certainly possible.
Video of the moment was posted Monday on Facebook and it shows shark expert Dr. Greg Skomal clearly caught off guard as he hung over a pulpit fastened to the bow of the boat.
Katarina Zarutskie was holidaying in the Bahamas, with her boyfriend and his family when she made a decision to pose for a photo swimming with nurse sharks in the marina only for one of them to latch onto her arm and pull her underwater. "White sharks are wild and unpredictable animals", they said, warning everyone to stay vigilant while in water.