Dive Knife - Tips on buying a diving knife that meets your scuba needs

A dive knife is probably the most important piece of scuba accessory you will need to ensure your safety during your dives. I am talking from experience here. Within my first months of enjoying recreational scuba diving, having invested in all the scuba gear with the exception of the scuba diving knife, I was under the false impression that I had it all together. I merely saw dive knives as an accessory with the probability of me getting entangled during a dive highly unlikely. I was dead wrong. In fact the scuba knife has been a life saver on two different wreck dives.

Were it not for this simple piece of scuba gear, maybe you would not be reading this article right now.

Besides being a life saver, a dive knife has got various uses like prying, digging and cutting or even grabbing your buddy’s attention underwater simply by pounding on your scuba tank.

There are different varieties of dive knives and they come in all shapes and sizes. Not any knife will do for diving. Your choice of which dive knife to go for is extremely important. Investing in the right diving knife should be made a priority to ensure your safety during your dives.

The first thing you will need to consider is the intended use of your scuba diving knife. Dive knives used by commercial and technical divers will vary from those used for recreational diving.

A good scuba knife is different from other convention knives due to the metal used during construction and the design of the blade and handle. A proper dive knife should have a sheath with a holder, is at least be made from stainless steel, and have both a sharp cutting edge and serrated sawing edge.

Factors to consider when buying your dive knife

Sheath with a retainer

An important characteristic of a dive knife is it’s sheath for strapping it on your body or scuba gear. The sheath must securely keep in place your knife yet allowing you to rapidly release it with one hand.

You may want to consider the design of the sheath, which may give you a choice in wearing the knife in the inside of your calf, on the thigh, arm or weight belt or carrying it attached to an instrument console that is part of your Submersible Pressure Gauge (SPG).

If you prefer to choose the leg mounted alternative, be sure to wear the diving knife on the inside of your calf opposite the dominant hand. It is important that you never place the knife on the outside of your calf. In the event you need to make an emergency ascent, on releasing your weight belt, the last thing you would want is for the belt to get entangled with your scuba diving knife.

An increasingly popular solution be used by divers is a BCD mounted diving knife. In my opinion a smaller BCD or SPG mounted knife is better suited for scuba. You will have one less piece of scuba gear to wear. If properly strapped to your BCD, you are also unlikely to forget to strap it on before your dives.

If you choose this option, you will however have to make sure that the diving knife is specifically designed to be mounted on your equipment. An equipment mounted scuba diving knife should have a blunt tip so as not to prevent accidentally puncturing a hole in your scuba gear when you sheath the knife during a dive.

Blade Size

The size of the blade is another important feature you will need to consider when investing in your scuba knife. Contrary to popular belief, large dive knives can be impractical to use. In fact for diving you do not really need a large bladed knife.

As long as the knife can do its intended job and can be adequately gripped, then a smaller scuba diving knife is more than suitable.

Shape of the knife

Dive knives come in a wide variety of shapes all have their specific uses. The shape of your scuba diving knife will determine its effectiveness for its intended use. As we have previously discussed blunt blades are ideal for mounted gear dive knives. On the other hand, pointed tip blades are ideal in spear fishing or for prying objects open.

As for cutting, there are three variants of dive knives to choose from specifically in the design of the blade. These come in the form of Serrated, sharp or a combination of both types of blades. I recommend that you go for the blade offering both combinations.

Another feature you may want to consider having is a metal handle butt. This comes useful as it doubles up as a hammer where you can easily grab your buddy’s attention by banging the metal handle butt on your dive tank.

Steel or titanium dive knife? Which is better?

Most dive knives are made of stainless steel, which usually fall between the 300 and 400-series alloys. However the down side of stainless steel dive knives is that they are susceptible to rust. This is because steel knives have a high level of carbon in them which provide the steel with extra strength.

After repeated use, they'll show a bit of rust so you will need to frequently maintain your diving knife. Special care should be taken after each dive by simply rinsing the diving knife using fresh water. Further rust prevention can be taken by simply rubbing down the blade with oil.

On the other hand while being much expensive than their counterparts, a titanium dive knife will last forever and can hold a sharp edge longer without needing any form of maintenance. Like most of your scuba gear, when choosing your scuba knife try to go for the high end, you are better off in the long run. So my recommendation is to go for a titanium dive knife.

Conclusion

Your dive knife is not just any tool. It is one of the most important tools of all your scuba gear. However you can easily injure yourself or others so learn how to use your scuba diving knife properly. Use common sense and proper judgment keeping in mind that safety comes first when using your scuba diving knife.

Finally concluding on an important note, a dive knife should never be intended to be used as a weapon but should only utilized as a safety precaution during your dives.