The pretty, nondescript municipal centre is at Hansnes, which can be reached through an undersea tunnel from Tromsø, and the drive is about one hour. From here ferries depart to Vannøy, Reinøy, and Karlsøy. The few inhabitants of Rebbenesøy are served by a ferry from Mikkelvik on the western side of Ringvassøy.
Karlsøy is among the world´s most important exporters of dried and salted cod, with Portugal, Spain, and Brazil among the main markets. The population is almost totally dependent on fishing.