Two good examples of problems associated with the deck level use of swaged fittings. “Swaging” is a process where tubular stainless steel fittings are essentially “crimped” onto rigging wire under high pressure. Salt water and other such corrosive elements run down the wire and migrate into the fitting, initiating rust, which in turn expands, eventually causing the swage to rupture and the wire to pull free unexpectedly. The StayLocTM fitting on the left of the second photo is a much better way to go.
StayLocTM , NorsemanTM , and other such fittings mechanically grip the wire via a conical wedge inserted into center of the wire and fitting body that covers it – they also have the additional advantage of being reusable.