1: Dive Rite Titanium Shears
The beefy grips give plenty of leverage on the 1½-inch serrated and smooth blades, which slice easily through ½-inch nylon dock line and glide through multiple strands of heavy plastic line. The 420 stainless blades are titanium-coated for corrosion resistance (they’ll still need a thorough rinse after salt use). The sheath is secure and has multiple options for attachment, or it can be stowed in a pocket. Contact: diverite.com MSRP: $30

2. Atomic Aquatics T16 Titanium
A light, full-size knife, the TI6 weighs just 4 ounces. The 4-inch blade is available with a blunt or sharp tip; both have smooth and serrated edges and a line cutter. The handle is grooved for a sure grip and can be removed by unscrewing the titanium pommel. The hard plastic sheath can be mounted to a calf or BC strap and locks the knife in with a right- or left-release tab. Contact: atomicaquatics.com MSRP: $129.98

3 Scubapro X-Cut Titanium
The all-titanium X-Cut is pared down to the barest essentials in a knife — a sharp edge and a place to hold it. Less than 6 inches long and weighing barely an ounce, the X-Cut makes surprisingly easy work out of everything from thick nylon rope to heavy monofilament and netting. The skeleton handle provides a decent grip for its size, and the included soft sheath can be slipped unobtrusively into a pocket or mounted on a strap. Contact: scubapro.com MSRP: $82

4. Cressi Skorpion
If you’re looking for a big, rugged, capable knife that does the job and is easy on the wallet, this could be the ticket. More than 9 inches long, with a thick stainless clip-point blade, the Skorpion is tough enough to deal with anything you need to cut, saw, pry or hammer. The finger-grooved handle is made of grippy rubber and is pierced for a lanyard; the hard plastic sheath has a button release. Contact: cressiusa.com MSRP: $39.95

Not sure which type knife is right for you? Get our guide to the various blades on today's dive knives.

1. Seac Rip Race
This drop-point stainless blade is a full ⅛ inch thick along its spine, and its fine edge is razor-sharp. Less than 7 inches overall, the Rip Race has a comfortable removable handle and heavily grooved guards for a solid grip. The sheath has a thumb lock and comes with mounts for BC, hose or leg. Contact: seacusa.com MSRP: $97

2. Underwater Kinetics Remora Titanium
The Remora Titanium attaches permanently to a BC or regulator hose, so you’ll never forget it. The blunt-tip blade slices through rope, fishing line and other entanglements. A sheath attachment kit is included. It’s also available in corrosion-resistant Hydralloy steel. Contact: uwkinetics.com MSRP: $113.99

3. Hollis Titanium Line Cutter
Made from titanium, this cutter is less than 5 inches long and weighs a scant 1 ounce. The hooked end pulls right through thinner lines; the serrated edge works on thicker stuff. The soft sheath is nearly flat, has loops for horizontal or vertical mounting and keeps the cutter secure. Contact: hollis.com MSRP: $89.95

4. Spyderco Salt 1
Four inches long when folded, this leaf-shaped blade opens with a flick of the thumb. Made of H1 steel that won’t rust, the blade is available with a plain or serrated edge and a black-coated blade. The waffle-patterned handle grips easily and features a titanium clip that can be installed on either side. Contact: spyderco.com MSRP: $134.94