Definition of "sealine"

sealine

/ˈsiːlaɪn/

noun
plural sealines
1. The coastline, seaboard.
2. The horizon.
3. A line used for sounding.
  Quotations
  Yet what depths of the soul does Jonah's deep sealine sound!
  1851 November 14, Herman Melville, “chapter 9”, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley
4. A line used for fishing in deep water.
5. An undersea pipeline for oil, natural gas, etc.