Few boats are without at least one knife, but when you need a knife in an emergency, you need it immediately. Sailors should carry a folding blade that can be opened one-handed. The Assist Salt knife has a large finger hole for easy opening even with gloves on, a blunt tip and a dual straight and serrated blade for cutting different kinds of line. It even has a built-in whistle. $170, www.sypderco.com