The Fishery Protection Squadron shares responsibility with other RN vessels and Service Commands for two most important duties. The first of these is the patrol in the waters around Northern Ireland against gunrunners. This is demanding work and, at times, very dangerous. TON class MCMVs and smaller craft are usually employed. The Royal Navy has developed, drawing from its experience in Confrontation and in Hong Kong, great skill in dealing with suspicious and possibly armed vessels.
The second task, oil rig protection, falls mainly upon the ISLAND class, although TONS
The Island Class patrol vessel HMS ORKNEY (920 tonnes standard displacement. 60 m overall, built 1977, one 40 mm gun. speed 16 knots, complement 34).