 Pockmarks were discovered off the coasts of Nova Scotia, Canada in the late 1960s by Lew King and Brian McLean of the Bedford Institute of Oceanography.They were discovered off Nova Scotia, using a new side scan sonar developed in the late 1960s by Kelvin Hughes.Before the two researchers King and McLean used the side scan sonar, they had noticed 'notches' on echo sounder and shallow seismic records in the seafloor off Nova Scotia.They believed these notches to represent gullies and curvilinear troughs in the muddy seafloor.