Add to cart Nautilus Lifeline – Marine Rescue GPS $339.00 The Nautilus LifeLine Marine Rescue GPS is more than a PLB, more than an EPIRB, and more than a satellite messenger. Communicate directly with boats and ships around you. Divers. Sailors. Paddlers. Nobody should be on the water without one. Compact. Super tough. Affordable. You might not think you need one until you do!!