bottomry

 A contract in the nature of a mortgage, by which the owner of a ship, or the master as his agent, hypothecates and binds the ship (and sometimes the accruing freight) as security for the repayment of money advanced or lent for the use of the ship, if she terminates her voyage successfully. If the ship is lost by perils of the sea, the lender loses the money; but if the ship arrives safe, he is to receive the money lent, with the interest or premium stipulated, although it may, and usually does, exceed the legal rate of interest. See Hypothecation.  [1913 Webster]