UK Dive Knives
Built Strong, For A Lifetime Of Use
Why do divers carry knives?
Every dive instructor will tell you that you should never dive without a scuba knife. Most people heed this advice, but probably don't spend a lot of time choosing the right knife.
Why bother? A knife's a knife, right?
In a word: No.
A dive knife is a safety device, a fishing implement, and a valuable tool.
When one thinks of safety devices, underwater knives are probably not the first thing that comes to mind.
But first and foremost, that's exactly what a diving knife is. We're not talking about trying to take on a Great White looking for lunch. We're talking about unforeseen objects that can entangle a diver and his equipment like kelp, netting, monofilament, and rope.
A quality, serrated-edge knife must always be accessible to free yourself from such situations.
An underwater knife is a must for fishing beneath the ocean's surface. It can be used to break up chum, loosen scallops, spear fish, or even fillet your catch.
As a tool, the diving knife has many uses. It can serve as a light pry bar, a screwdriver, a hammer, and an equipment modifier above the surface, when there are no other tools available.
If you want a safe and enjoyable scuba diving experience, your dive knife is simply indispensable.
What to look for in a dive knife.
As you have probably already gathered, dive knives come in a host of sizes, configurations, and materials. Each of these variables has its strengths. Our intent is to help you select the right knife for the type of diving you intend to do most.
The biggest difference you will notice in dive knives is in their blade types and the features they possess. We know it can be a bit confusing, but it becomes simple when you consider that each blade type has its own unique function. It all boils down to a matter of learning which blade works best in the situations you may encounter most.
Drop and Standard Point
If it weren't for that pesky regulator, you could do your descent with one of these blades clenched in your teeth, scaring everything in your path. Ok. This is the blade that you want for undersea game as it has a pointed tip. The straight edge becomes a curve which actually lengthen the knife's cutting surface. The longer cutting edge is made for cutting chum, bait, and general sport fishing applications.
Again this blade has the serrated safety edge on the back side. Look for a metal that holds a keen edge over prolonged use.
A blunt tip blade is ideal for the diver who is more interested in using the knife as a tool. The abbreviated tip reduces the likelihood of break-offs during prying situations. Note that no matter how strong your knife is, it really shouldn't be used as a full-fledged pry bar. (that's what full-fledged pry bars are for)
There are two types of cutting surfaces on this type of blade: one edge is serrated for cutting your way out of entanglements and the other is straight for general cutting. When considering a blunt tip, look for the strongest metal as the foremost characteristic.
The Emergency Blade
No matter what type of diver you are, this type of blade should be carried not as your only knife, but as the name implies, your emergency knife.
The emergency blade has only one cutting surface and it is serrated. Serrated edges are proven to be the quickest and easiest way to free yourself from unforeseen entanglements such as netting, rope, monofilament, and kelp.
They are also the shortest of the dive knives in order to remain unobtrusive and out of the way until they are needed. The rounded back and tip of the blade greatly reduces the potential of puncturing your BC upon returning the knife back to its sheath after use.
Since this blade is not frequently used and may get overlooked during your post-dive clean up, we recommend a metal that is geared toward corrosion resistance.
Dive Knife Features
The knife that your dive instructor told you to never dive without, is first and foremost, a safety device. Its main purpose in the big picture is to free yourself from unforeseen entanglements. A serrated edge will do this best. Properly spaced serrations in a blade make it easier to free a diver from potentially dangerous situations. Always make sure that you have a serrated edged blade knife on every dive.
Hooked Line Cutter
This is a handy little feature that makes short work of cutting through monofilament fishing line and light netting.
This is the base of the blade and it should not be sharpened as it is sometimes necessary to wrap your index finger around it. By doing this, it allows you to get your hand a bit closer to the task you are working on in order to gain greater control of your knife.
Plain and simple: It's made for general cutting. For best and safest operation, keep the edge keen. Here's something that you may not have known: More people are hurt from using a dull cutting instrument than a very sharp one. The reason is that one has to exert more force on the dull instrument to make it cut and that exertion of force causes one to compromise control of the instrument.
Useful for signaling other divers by tapping on your tank. It can also be used as a makeshift hammer or mallet. Its main function is as the final locking piece that secures the blade's tang to the handle. Make sure that there is no metal-to-metal contact.
Ease Of Disassembly
It's important to take your dive knife apart after each dive and rinse off the saltwater - unless you like pulling your knife out of the sheath and finding an orange stub where your blade used to be. Get a scuba knife that comes apart quickly and easily to make cleaning effortless.
It's the part that you've got to make physical contact with when you plan to use your dive knife. Sometimes these periods can be lengthy. Make sure the experience is a comfortable one. Look for an ergonomic design that fits comfortably in your hand. Also check into the materials and ensure that they are of the non-slip variety when wet.
Where Should A Dive Knife Be Placed?
Where and how a diver is going to mount a dive knife is another important consideration. It is important that the diver wears the knife in a way that is secure and easily accessible.
The traditional mounting of a dive knife is by straps on the leg, just below the knee. Some divers attach the knife inside the leg to avoid snaring on kelp. This is still the way most larger knives are mounted. However, this is not the most convenient location, especially in the event of an emergency.
Many scuba diving professionals are now teaching that a knife should be attached to the upper body where it is more accessible.
It is now common to see knives attached to the BC. Some of the ways to attach the knife to the BC are Hose Attachment, to the fabric of the pocket or straps, and to manufacturer installed mounting grommets.
It has become common for a diver to carry an emergency-type knife on his torso in addition to the larger traditional leg-mounted knife.
What Is The Best Metal For A Dive Knife?
Titanium Blades - Never Corrode
The best metal for a knife blade -- as far as strength-to-weight, edge retention, and corrosion resistance is concerned -- is titanium. A titanium blade will never rust or corrode. The only drawback is that it is expensive.
We make our dive knives out of an aircraft grade of titanium alloy that is specially heat-treated to remain tough enough for prying yet maintain a sharp edge. Our titanium knives will surprise you with how little they weigh. Unlike other brands of titanium knives, our pommels are also turned from titanium.
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Stainless Steel Dive Knives
A more affordable alternative would be stainless steel, however stainless steel and saltwater don't get along too well. All stainless steel knives corrode in saltwater, some more than others.
The "X" factors here are the amount of carbon and chromium contained in the metal. High carbon and low chromium content in the 400SS series knives make them more rigid and keen edged, but highly susceptible to corrosion.
Conversely, the low carbon content and higher chromium content of the 300SS series dive knives make them easier to dull and bend. On the plus side, they will resist saltwater corrosion a lot more.
There is another option: Underwater Kinetics' proprietary metal - HYDRALLOY.
HYDRALLOY - The solution to corrosion
At Underwater Kinetics we gave our team an assignment: create a dive knife that is strong and keeps a keen edge comparable to 420SS, resists corrosion like 316SS, and is around half the cost of a titanium knife.
Our solution: HYDRALLOY.
HYDRALLOY is a special alloy that combines the best qualities of 316 and 420 steel to produce corrosion resistant blades with great strength and sharpness.
Previously, there was not a commercially available stainless steel which had a combination of being hard enough to maintain an edge, tough, yet stiff enough for prying, and did not rust in salt water.
By combining a unique blend of alloys and proprietary finishing techniques, we've developed a superior new brand of stainless steel for dive knives.
Our constant quest for perfection lead us to have custom mill runs of our proprietary steel formula which not only has different alloy content but a different heat treating process than other dive knives. One would not think there would be a big difference in testing dive knives, but there is a huge one between ours and other makes. UK's cut significantly better than any other brand through a variety of different material while having higher prying strength without bending or breaking while still being corrosion free.
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Underwater Kinetics Diving Knives
A Cut Above
American Made Quality
We make dive knives out of two different metals: Titanium, a strong lightweight metal that resists corrosion and holds an edge well, and HYDRALLOY, a special alloy that combines the best qualities of 316 and 420 stainless steel to produce corrosion resistant blades with great strength and sharpness. Combine this with other great features like a hooked line cutter and serrated edge and you’ll soon discover why our knives consistently top the gear review charts.
Full Length Blade
Quality knives are always built with a blade that runs the full length of the knife. This gives you increased strength when using it for prying tasks. Some knives have the blade stop at the handle, resulting in a weak point and most often, a broken knife.
BONUS: All UK knives are easy to disassemble for cleaning without the use of tools!
Built To Remain Corrosion-Free
When metal comes in contact with other metal, it conducts electricity and that causes corrosion. Our knives are some of the most durable because we avoid metal to metal contact in our designs.
In the image to the left, you can see the UK knife (top) is designed so that the knife blade and the pommel are separated by a plastic connector thus avoiding any metal-to-metal contact. The competitor's blade (below) attaches directly to the metal pommel which will eventually cause corrosion.