Scrabster's on the north coast of Scotland just west of the Pentland Firth, Gillnetting is a method of fishing useing Gill nets (the fish got caught by the gills when they swam into the net)they were shot on the bottom and left for so long ,something like large meshed herring nets shot on the bottom instead of the surface, the boats that wull has been posting took a hell of a lot o cod from the Pappa Bank and other banks up north,
Yes, Gill-netter is the type of fishing carried out by this boat.
Lengths of net, typically each about 100yds long x about 7ft high (although the height can vary greatly) are set along the seabed & bottom dwelling fish literally swim into the net (as it is nearly transparent) & get caught by the gills. Smaller fish swim through the meshes of the net without getting caught.
Variations on this method include wreck netting which is setting nets around wrecks to catch the fish that live within the wreck & tangle netting where the mesh of the net is really slack to catch flatfish & shellfish.
Scrabster is at the Northern tip of Scotland.