During Dive 03, we conducted two transects up the eastern wall of McMaster Canyon, approximately 80 miles south east of Long Island. Remotely operated vehicle Deep Discoverer (D2) landed on a silty sedimented seafloor with eels, sea urchins, fish, and several instances of anthropogenic debris.  During the first transect, the lower portion of the canyon wall was chalky and highly sculpted with little benthic life. Further up the wall, D2 encountered several large colonies of octocorals and high-density groups of cup corals, anemones, bivalves, and sponges. Transect two show similar patterns and high diversity as seen in Hendrickson Canyon, with large groups of corals living under overhangs and outcrops along the steep wall. Other fauna encountered during the dive included several swimming sea cucumbers, sea stars that our experts have never seen alive, squat lobsters, brittle stars, a king crab, and octopods.