Men are stupid about knives. It's one of those subjects like guns and fast cars that gets the old testosterone flowing. And we all know what effect that has on clear thinking.

As a result, too many dive knives look like Steven Segal action figure weapons. The latest trend is the "tech" look with an ultra-thin "skeleton" steel handle. They come finished in black, too, for midnight murder. So the obvious needs repeating: A dive knife is a tool for cutting stuff under water--not an anti-terrorist weapon.

Knives in Review

Following are 15 dive knives that more or less meet the criteria set out in the "How to Buy a Dive Knife" section at the end of this article. Most models are also available in sharp-pointed versions.

I tried all knives against half-inch nylon rope (the typical anchor line), one-eighth-inch polyester with a Kevlar core (Kevlar is very hard to cut), one-eighth-inch nylon twine (commonly used for fishing nets) and 30-pound test monofilament. All these knives did the job, some faster than others, as noted.

Rating System:

Excellent *****
Very Good ****
Good ***
Fair **
Poor *

Akona Sidekick

Rating: ***

The Sidekick's line cutter is placed at the middle of one edge, where it's more accessible than on most knives. The blade guard is good, a wide V, though the handle is a bit short. The sheath has a unique release/engagement mechanism that's easy to use. Release is smooth and engagement is positive. There's no provision for bolt-mounting, though, just straps or belt and strap. With a butt cap and lanyard hole.

Length and thickness with sheath: 9 inches by 1.4 inches.
Blade length: 4 inches.
Blade material: 420 stainless steel.
Serration type: Coarse.
Handle length: 3.8 inches.
Price: $55.
Contact: Akona Adventure Gear, (949) 581-8069.

Beuchat Maximo Pocket Knife

Rating: ***

The problem with a folding knife is that it may require two hands to open it. This one can be opened one-handed--but just barely. A lot of the blade projects from the handle, and a slot cut in it gives something to get your thumb into. This also makes it reasonably easy to manage when wearing gloves. Assuming you can open it, a folding knife makes some sense, because when it's folded, it's smaller than any BC knife and easily fits inside a pocket. When extended, it has a full-sized grip and a nearly full-sized blade. The lower edge is half plain, half serrated with the wavy style that can be sharpened on an ordinary stone. The plain portion has considerable "belly," or curve, to improve sawing. The line cutter is near the point, where it should be, and is equally useful when the knife is folded. The blade locks open when extended so you can't accidentally close the blade on your fingers; press a bar on the back of the handle to release the lock.

Length and thickness with sheath: 4.7 inches by 0.6 inches folded; 8.4 inches by 0.6 inches extended.
Blade length: 3 inches.
Blade material: 301 stainless steel.
Serration type: Wavy.
Handle length: 4.5 inches.
Price: $36.
Contact: Beuchat North America, (305) 548-3483.

Cressi-Sub Norge

Rating: ***

The handle of this knife is comfortable, and the grip feels secure. The guard is a good one. The blade is made from stainless steel, alloy unknown. Its upper edge has a section of serrations fine enough not to snag most fibers, but it's short (1.5 inches). Scallops are cut on one side of the blade only, so you can sharpen them easily. The sheath releases easily and engages positively.

Length and thickness with sheath: 9.5 inches by 1.2 inches.
Blade length: 4 inches.
Blade material: Stainless steel.
Serration type: Medium.
Handle length: 4 inches.
Price: $55.
Contact: Cressi-sub, (800) 338-9143.

Dacor Mikado and H2Odyssey Tiger

Rating: ***

These two knives are identical, except the Tiger has a butt cap. Serrations have rounded tops so they don't catch fibers. They saw well. They are one-sided, and can be easily sharpened. The plain edge cut only fairly well, but a file would improve it. The guard is only fair: the finger side is not well-protected. The sheath has an easy release and positive engagement, but strap mounting only.

Length and thickness with sheath: 9.5 inches by 1.3 inches.
Blade length: 4.5 inches.
Blade material: 420 stainless steel.
Serration type: Coarse.
Handle length: 4.3 inches.
Price: Dacor, $40; H2Odyssey, $39.
Contact: Dacor Corp., (800) 323-0463; H2Odyssey, (760) 599-4097.

Deep See Wenoka Razorback

Rating: **

This knife has only one edge, serrated, plus a ceramic line cutter. The serrations are only medium in size, but with sharp tips that tangle line fibers. That makes cutting loose loops of line difficult. The teeth are one-sided, so they can be sharpened easily. The ceramic blade is extremely sharp and cuts monofilament and even Kevlar, but is too short for slicing. The guard is far from foolproof. It would be easy to slip your thumb onto the razor-sharp ceramic blade. The sheath release requires a hard pull, and engagement requires pushing hard too. Attachment options include thumb screws and a belt loop.

Length and thickness with sheath: 7.4 inches by 1.3 inches.
Blade length: 2.2 inches.
Blade material: 304 stainless steel, ceramic line cutter.
Serration type: Medium, only edge.
Handle length: 3.5 inches.
Price: $69 to $75.
Contact: Deep See, (800) 367-2626.

H2Odyssey Titan

Rating: ****

The plain edge of this knife has a fair amount of "belly" (curve), which helps it slice. Thanks also to a slightly rough edge, this was the best-cutting knife in the group. The serrations on the upper edge are of the wavy type that cut well without snagging. They are two-sided, however, and will be difficult to sharpen. The handle is excellent with a good grip and guard. Fingers are especially well-protected. Releases from sheath easily, but engagement requires a firm push to a second click; otherwise, you may think it is engaged when it's not. Strap mounting only.

Length and thickness with sheath: 10 inches by 1.3 inches.
Blade length: 4.4 inches.
Blade material: Titanium.
Serration type: Medium, wavy.
Handle length: 4 inches.
Price: $89.
Contact: H2Odyssey, (760) 599-4097.

IDI Titanium and Sport Divers Manufacturing Titanium

Rating: ****

These two knives have identical blades, and the same excellent handle as the H2Odyssey Titan. The pointed tip is very sharp, but you could grind it off. It does give the plain edge more "belly," so it slices even better than the Titan. The serrated blade, unfortunately, is as bad as it could be. It's short, the teeth are sharp fiber-grabbers and the scallops are cut from both sides of the blade, making sharpening a chore. The sheath is a little better than the Titan's, however, with an easy release and a single-click engagement.

Length and thickness with sheath: 10 inches by 1.3 inches.
Blade length: 4 inches.
Blade material: Titanium.
Serration type: Coarse.
Handle length: 4.5 inches.
Price: IDI, $69; SDM, $90 to $100.
Contact: International Divers, (800) 257-2822; Sport Divers Manufacturing, (305) 947-5692 (for dealer information).

Oceanic Probe

|| |---| | | | Oceanic Probe| Rating: ***

This is a pretty good knife handicapped by a poor sheath. The blade is a conventional design, although the double-sided serrations won't be easy to sharpen. The handle is a big one that gives a good grip, and the guard is ample. But the sheath does not release smoothly. If you pull the knife at an angle, the line-cutting notch in the blade catches the sheath. Also, returning the knife to the sheath requires a hard push, and if the knife isn't straight, it may not engage the catch. Strap mounting only.

Length and thickness with sheath: 10 inches by 1.3 inches.
Blade length: 4 inches.
Blade material: 420 stainless steel.
Serration type: Coarse.
Handle length: 5 inches.
Price: $49.
Contact: Oceanic USA, (510) 562-0500.

**Oceanic Tiburon **

Rating: ****

One of the best things about this knife is the guard, a sort of D-ring that fully encloses your fingers. It makes this knife the safest to use and the hardest to drop. The plain edge has lots of "belly," and appears to be slightly rough, because it slices rope far better than most other dive knives I tested. The serrated section is good, too, with rounded tips that don't snag fibers and the one-sided design that's easily sharpened. They function as monofilament cutters too. A bottle opener and nut turners are extras not often seen on a dive knife. The sheath is a good one with an easy release, positive engagement and a belt loop.

Length and thickness with sheath: 10.2 inches by 1.4 inches.
Blade length: 4 inches.
Blade material: Stainless steel.
Serration type: Medium.
Handle length: 5 inches.
Price: $84.
Contact: Oceanic USA, (510) 562-0500.{mospagebreak}

Oceanic Titanium

Rating: ***

This knife has an odd design. Serrated and plain sections share one edge of the blade, so each is short--only two inches. The serrations are the wavy style, which cut well, but are cut into both sides of the blade, so will be difficult to sharpen. The blunt end is sharpened too. The guard is merely a bulge in the profile of the blade, but has teeth to grip your thumb and fingers. The sheath grips mostly by friction and requires lots of force to withdraw and replace the knife. Be sure you push it in all the way. Holes in the perimeter of the sheath permit bolting it to your BC, and the whole package is very thin.

Length and thickness with sheath: 10.4 inches by 1 inch.
Blade length: 4 inches.
Blade material: Titanium.
Serration type: Medium, semi-wavy.
Handle length: 5 inches.
Price: $120.
Contact: Oceanic USA, (510) 562-0500.

Scubapro K-3

Rating: **

This would be one of those too-small BC knives except that the handle is well-designed to give a secure grip. Hook your forefinger over the guard, which hooks against your second finger. Your thumb grips notches in the top of the handle. The 'skeleton" handle is still likely to be slippery, however. Wavy serrations plus some belly to the edge help it cut pretty well. The serrations are cut on one side of the blade, so you can sharpen them with a conventional stone or file. Releasing the knife from the sheath involves rotating a small knob 90 degrees, which may not be easy if you"re wearing gloves and can't see the knife.

Length and thickness with sheath: 6.8 inches by 0.8 inches.
Blade length: 2 inches.
Blade material: Stainless steel.
Serration type: Fine, wavy (only edge).
Handle length: 3.5 inches.
Price: $55.
Contact: Scubapro, (619) 402-1023.

Sport Divers Manufacturing BC Knife and H2Odyssey Thresher

Rating: ***

A wavy serration on the single edge allows this knife to cut everything extremely well. The knife rips through rope and Kevlar, and snaps monofilament instantly. The blade is scalloped on one edge only, which would make sharpening easy except that edge is hollow-ground--concave. Using a flat stone will ruin it, so you"ll have to sharpen the teeth individually with some tiny files or stones. On the other hand, a serrated blade doesn't require sharpening very often. The handle is short and the guard is low, so it seems that you"re supposed to put your thumb and index finger over it. Fortunately, the first half-inch of the blade is not sharp. The sheath has a one-finger release, but the engagement is not foolproof. It can be mounted with straps, on a belt, or by two screws.

Length and thickness with sheath: 7.3 inches by 1 inch.
Blade length: 2.4 inches.
Blade material: 420 stainless steel.
Serration type: Wavy.
Handle length: 3.5 inches.
Price: Sport Divers Manufacturing, $25; H2Odyssey, $19.
Contact: Sport Divers Manufacturing, (305) 947-5692 (for dealer information); H2Odyssey, (760) 599-4097.

|| |---| |

| | Sport Divers Manufacturing Skeleton| Those Tech Knives

OK, you wanted to see them, so here are a couple. Wicked, eh?

The only advantage of these knives (to a diver, not a terrorist) is that they are thin. They can lie flat against your leg or whatever with less chance of snagging something.

The major disadvantage is that the thin polished handle can be hard to grip if it's wet, your hands are cold or you're wearing thick gloves. A knife isn't much good after you drop it into the abyss. The blade guard is pretty minimal too.

Ocean Reef Tek Knife ($62; in black, $66) and Sport Divers Manufacturing Skeleton ($20).

How to Buy a Dive Knife

Shopping for a dive knife? Take a cold shower and look for:

Medium length. Small enough that you have a chance of mounting it on your BC, large enough to grip securely. The only reason for strapping a knife to your leg is that it's too big to go anywhere else. The typical medium knife has a 4-inch blade on a 4- or 5-inch handle. Tiny "BC knives" have come on the market, which can even be clamped to a hose, but remember that you"ve got to be able to grip the thing pretty securely.

A plain edge. For cutting small lines that would be caught between the teeth of a serrated edge. An edge sharp enough to shave your forearm is not as useful as a slightly rougher edge. You won't be shaving under water; you"ll be slicing, which is a form of sawing and benefits from having microscopic teeth on the edge. If the plain edge has some "belly," or curve, it slices much better than if it's straight--probably because the point of attack is constantly changing.

A serrated edge. For sawing thick ropes, like the one that's wrapped around the propeller shaft. Wavy or rounded serrations generally cut rope better than big, sharp saw teeth, which often snag the fibers of the rope. On most dive knives, serrations are more ornamental than useful. They should run nearly the full length of one edge of the knife so you can get a good sawing motion going, and they should be near the tip of the blade because you may have to get it into a tight spot (like between the propeller and the hull).

A line-cutting notch. For snapping monofilament. Snagging the monofilament in one of the serrations usually works as well.

A blunt tip. Sharp tips are for stabbing people, most likely yourself. OK, you might want to work a sharp point under a tightly wrapped line so you could cut it. But a blunt tip doesn't have to be as blunt as scuba knives typically are. A quarter of an inch is enough to keep it from puncturing your BC--or you. If you buy a knife with a sharp tip, grind a bit of it off.

An effective guard. It's the part between the handle and the blade that's meant to prevent your fingers from wandering onto the sharp edge. The best ones have a bit of a hook on the bottom side to catch your forefinger, and a thumb rest on the top side.

A full-sized handle. So you don't drop it. It may be slippery and your hand may be cold and stiff, so you should be able to get all four fingers around it. Remember, you may be wearing gloves.

A lanyard hole. In case you do drop it. You could put a wrist thong here too.

An intelligent sheath. Look for one with a release operable by one finger of the hand that's grabbing the knife. It should let the knife withdraw smoothly. When you return the knife to the sheath, it should engage positively with a clearly heard or felt "click." The sheath should also have mounting options beyond the usual pair of leg straps, like a belt loop and bolt holes.

Corrosion resistance. Most dive knives are made from stainless steel, usually the 306, 420 or 440 alloys. Higher numbers mean less corrosion resistance, but more ability to hold a sharp edge during use. Corrosion resistance is more important than hardness if, like most of us, you"ll use your dive knife only in a rare emergency. With any luck, you"ll have plenty of time to sharpen it again before the next emergency. That's why corrosion-resistant titanium makes such a good dive knife: sharpen it once, and as long as you don't use it, it will be just as sharp 100 dives later. A harder stainless steel knife would have lost its edge to corrosion long before.

Dive Knife Maintenance Tips

To sharpen a plain edge: Use a file, not a stone. The edge will be sharp but rough, as if it had tiny serrations. It will slice through any rope much faster than a stone-sharpened edge. As with a stone, try to keep the file at a constant angle and file both sides equally.

To sharpen a serrated edge: If the serrations are cut only on one side of the blade, you're in luck. The easy way to sharpen it is to take a stone to the other edge and sharpen it as if it were a plain edge. But if the serrations are cut on both sides, you'll have to use a bunch of tiny files or stones. Jigs and special tools are available to make the job a little easier, but it will still be slow. One source is Spyderco: (800) 525-7770. Fortunately, serrated edges can go a long time between sharpening.

To prevent corrosion: Yes, stainless steel does rust--some alloys more than others. Rust attacks the thin edge first, so the knife gets dull before it looks really bad. Wash the blade with fresh water after every dive, and scrub it to remove the film of salt that will otherwise stay behind.

Can you coat the blade to keep seawater off? You might coat it with silicone spray or grease, but of course this will wash off pretty quickly. Petroleum-based waterproof grease lasts longer, but will attack anything silicone it comes in contact with so be careful. And with either, the problem is to get anything to stick to the sharp edge itself.