The Collaborative International Dictionary of English v.0.48:

Haaf \Haaf\ (h[aum]f), n. [Of Scand. origin; cf. Icel. & Sw. haf
   the sea, Dan. hav, perh. akin to E. haven.]
   The deep-sea fishing for cod, ling, and tusk, off the
   Shetland Isles.
   [1913 Webster]