When people talk about the Final Frontier, they often look to the heavens as a vast place that's yet to be fully explored. But the reality is that there's a Final Frontier closer than you might think: the oceans. Diving deep into the abyss is one of the most exhilarating and awe-inspiring outdoor activities around.
Still, the reason the oceans are dubbed the Final Frontier is because of their mystery and potential for danger, which is why it's important for divers to be well-equipped. One of the key tools you should always have on you when you're diving is a knife. Below you'll find some of the things to look for in a good dive knife.
Why Do I Need a Dive Knife?
First, let's start with why you'd need to take a knife on your dive in the first place. A diving knife has many uses, including cutting lines or nets, prying objects, and digging. Getting trapped or caught in discarded nets and lines is an unfortunate possibility, which is why you need something that will help you escape quickly and safely.
In other extremely rare instances, a dive knife may be used in self-defense against the many predators of the sea. This is a relatively unlikely occurrence and a knife might not necessarily be the best thing to use, but dive knives have prevented attacks while in the oceans. In one instance, a stranded windsurfer used a knife to fend off a pack of hungry sharks.
Dive Knife Considerations
If you browse through our selection of dive knives, you'll notice a variety in styles and features. It's important not to just pick any random knife—especially since it's something your life may depend on. We've broken down some of the things to consider when picking the right dive knife for you.
Serrated vs. Plain Edge
The debate between serrated and straight edges has been raging since the serrated knife was first invented. This debate is important to consider when buying a diving knife because the two types of blade edges have different uses.
Since the main purpose of a dive knife is to cut through ropes or stronger material, a serrated blade is the way to go if you're only given one option. Straight edges are best used for cutting lines and finer things.
Many diving knives offer both a serrated and plain edge—one on each side of the blade. Normally, you wouldn't want this on a knife, but dive knives are not used to puncture things, so it's advantageous to have an edge for cutting rope and an edge for slicing things.
Another important aspect of a dive knife is its handle. Because you're in or around water, things tend to be slippery. Texture, shape, and material are all things to consider when selecting a dive knife.
A textured handle will keep the knife firmly in your hand while its shape will make it easier to hold.
A sheath is equally important because it's the only thing that prevents your knife from sinking away into the abyss when you're not using it—which is a vast majority of the time. But when the time comes to use it, you need to know the knife will be there. A reliable sheath is one that fits properly on your body or equipment and has a sheath retainer, which is a device that prevents your knife from coming out unexpectedly.
If you happen to be using a folding dive knife, many come equipped with clips instead.
Blunt vs. Pointed Tip
You'll find two types of knife tips—blunt and pointed. This is often a matter of preference, but let's break down the differences. Unlike pocket knives, you don't necessarily need a pointed blade on a dive knife because it's rarely used for stabbing and piercing. A blunt knife makes your knife much safer in the unstable underwater environment.
Other people will only dive with a pointed blade because it may come in handy during a shark attack, which, again, is a rare occurrence. This is something you'll have to take into consideration depending on how you plan to use the knife.
Many blades on dive knives are made from stainless steel, but stainless steel is rust-resistant, not rust-proof. After excessive exposure to water, stainless steel knives can rust, something you don't want to happen to your dive knives. Higher grade stainless steel will typically hold up much better in the water, so you don't need to rule it out completely if you have your eye on a knife that's stainless steel.
Still, titanium blades usually perform much better in the water and essentially never rust. A downside of titanium is that it has the propensity to chip during certain tasks.
Then, of course, there's H1 steel. This is a fairly new type of blade steel that's essentially rust-proof. It is precipitation-hardened steel that uses 1% nitrogen instead of carbon. H1 is found in Spyderco Knives.
Fixed vs. Folding
Believe it or not, folding dive knives have made some waves in the dive knife world. Normally, we'd only recommend fixed blades because of their reliability, but the recent strides made in steels and materials make folding knives realistic options. Spyderco folding dive knives can stand up to many dive knives with fixed blades; however, they have the added convenience of taking up a smaller space and being safer to carry.
If you're a traditionalist, a fixed blade is the way to go, but a folding dive knife is no longer fringe and should definitely be considered.
One of the primary uses of a diving knife is to cut lines, especially those fine lines you might get tangled in. The knife itself is adequate at cutting the line, but many dive knives come with notches in the blade that are designed specifically for this use. A line cutter on your dive knife is a great feature to have.
Another feature that comes in handy when diving with a team is a metal butt on the knife. This usually comes in the form of a metal cap at the end of the handle that acts as a tap hammer, which is useful when trying to communicate.
Ever wondered why some dive knives are bright and colorful? It's not just a fashion statement. These knives are highly susceptible to getting lost, especially if you happen to let it go underwater. By having a handle with some vivid accents, you'll be able to spot the knife from a distance.
Yet another trait you might want to consider is a lanyard hole. Not all dive knives come with them, but they can be convenient if you often find the knife slipping out of your hand. A lanyard around your hand will keep the knife nearby.
Dive Knife Recommendations
If you need help picking out a dive knife, here's a list of reliable dive knives available at Knife Depot.
Kershaw Sea Hunter
The Kershaw Sea Hunter has a pointed tip and a 420J2 stainless steel blade. On one side is a partially serrated edge and the other is a plain edge with a hook to cut lines quickly. The blade length is a reasonable 3.75 inches, and the handle is made from durable polymer. Bright accents on the handle make it easy to spot when visibility is low.
The sheath features adjustable straps and a quick-release latch that allows for easy access.
Benchmade is well-known for its tactical knives and AXIS-locking mechanism, so you may be surprised they dabble in the dive knife industry. However, these Benchmade dive knives consistently get high marks from divers.
The Benchmade 111H2O is a folding dive knife with a 3.45-inch blade made from highly corrosion-resistant N680 steel. It features a modified sheepsfoot blade with a straight edge and ambidextrous thumb studs. Its Grivory handles are textured for a strong grip and are bright yellow (though you can also get the handle in black).
It uses Benchmade's famous AXIS lock, which is extremely reliable. A clip makes it easy to carry.
Underwater Kinetics Dive Knife
Unlike the Sea Hunter, the Underwater Kinetics Dive Knife has a titanium blade and a blunt point for those who have a preference for those two features. This dive knife also has a line cutter and a straight and serrated edge. The butt of the knife can also act as a tap hammer.
The blade length is a little long at 5 inches, but it comes with a plastic sheath that allows you to carry it easily.
Spyderco Pacific Salt
Our final knife is yet another fixed blade. The Pacific Salt from Spyderco is very popular among divers (as is the rest of the knives in the Spyderco Salt Series).
This fully serrated 3.81-inch blade is made from H1 stainless steel, which is noted for being rust-proof. The Pacific Salt is made with the water lover in mind and is a great secondary tool to have on you. It may not be your idea of a traditional dive knife, but it consistently gets high reviews and praise.