Abstract: Provided herein is a Mooring Line Restrainer capable of withstanding the whiplash from the impact of a snapped mooring line, and including a contoured Restraining Member shaped to engage and restrain snapped mooring lines and incorporating a single or multi-turn spring, mounted on a framework attached to one or more support bases. At least one of the support bases is a magnetic holding device adequate for different sizes of mooring lines, for securely and strongly fixing the Mooring Line Restrainers on the deck of a ship at appropriate positions along and on either sides of the mooring lines as per a mooring layout plan. The support bases have provisions for interlinking the plurality of adjacent or alternate Mooring Line Restrainers for forming a strong structure around the mooring lines for confining and restraining any snapped mooring lines within a narrow zone around their pre-snapped positions on the ship's deck.