Whether you need a dive knife or not depends on what kind of diver you are and in what kind of waters you dive. For most recreational divers, carrying a dive knife is an extra safety precaution. Meanwhile, for spearfishers and professional divers, a dive knife is considered an essential part of scuba gear.
So the question is, do you really need a dive knife? If you’re planning on investing in a scuba knife it’s important that you know where the best place to store your dive knife is during a dive.
Do I Need a Dive Knife for Scuba Diving?
Can’t decide on whether you should get a dive knife? Here are some things to consider before you decide to buy one.
Are Dive Knives Mandatory Diving Gear?
A dive knife is not a mandatory piece of equipment for divers. However, frequent divers and professional divers may still prefer to carry one.
Dive knives are carried for safety reasons but not properly carrying or using a dive knife is also dangerous. Strong currents or lack of control can lead to cuts in the skin or piercing the diving gear.
In the end, it is a personal choice. When considering a dive knife, every diver should think about what it will be used for and in what type of waters.
What Are Dive Knives Used For?
There are a few reasons why a dive knife is useful. They can be used for spearfishing or for releasing oneself, a fellow diver or an animal from entanglement.
Divers in busy fishing waters run the risk of getting caught in monofilament lines or netting for fishing. Having a dive knife on hand quickly releases the diver from this situation.
The nets are also a reason why divers choose to carry a dive knife. Fishing nets are infamous for trapping other ocean animals as well so, divers are able to set these animals free before it is too late.
Another area with risk of entanglement is waters with a lot of kelp. Kelp can get stuck on protruding diving gear or even around the fins.
Technical divers are the most likely to carry a dive knife because they perform actual jobs underwater like maintenance. Another less common reason to carry a dive knife is for anchoring oneself in the sand during strong currents.
Are there Safer Alternatives for Dive Knives?
So now you have decided that a dive knife, or similar, should be part of your scuba gear, let’s explore another option for you, which perhaps is a safer one. 
There is an unconventional but very effective and safer alternative for dive knives; trauma shears. Trauma shears are the special scissors used by emergency respondents to quickly cut through clothing and other soft materials.
Trauma shears are not suitable for technical divers that need to perform underwater work. For most other divers though, especially recreational divers, trauma shears are enough to cut through fish nets, monofilament lines and kelp.
You are less likely to cut yourself or make a cut in your dive suit when using trauma shears. Another advantage is that trauma shears are easier to handle with one hand.
Tips for Choosing the Right Dive Knife for You
As mentioned, when choosing a dive knife to think about what it will be used for and in what kind of waters you are most likely to dive. Will you dive in an area with a lot of kelp or are you more concerned about getting caught in monofilament lines?
The type of blade, the design, knife length, material and tip all make a difference. Other than the dive knife specs in the buying guide, we have a few more tips to help you make your choice. Here are a few things to consider when deciding between dive knives.
You Don’t Need to Choose Between Edge Types
Many buying guides tell you about the difference between a serrated edge and a sharp edge. To recap, a serrated edge is
better at cutting through wider natural materials while a sharp edge quickly pierces through plastic and thin materials.
In reality, you are likely to need both kinds of blade edges. Fortunately, you are unlikely to have to choose between the two types.
Most good quality dive knives are fitted with both a serrated edge and a sharp edge. This way you get the effectiveness of two blades in one knife.
Carry Your Dive Knife in a Sheath
A dive knife with a fixed blade usually comes with a specially fitted sheath. This sheath is the key to preventing unwanted cuts in your diving gear.
The alternative is to carry a folding dive knife which also prevents cuts. However, keeping the knife in a sheath makes it easier to grab; you don’t have to struggle to fold it open with two hands.
Test How Comfortable the Handle Is
Having a good grip on the blade is important. The last thing you want is to injure yourself or have the dive knife slip out of your hand.
The grip should sit comfortably inside your palm, not too big and not too small. The material should also have some grooves in it so that it is not too slippery underwater.
Get used to the feel of the dive knife and how best to hold it in your hand before you go diving.
Get the Right Size for You
Aside from the grip, the rest of the dive knife should be a comfortable size, too. Most dive knives are between 2 to 6 inches.
Smaller dive knives are best for new divers and occasional recreational divers. A 4-inch dive knife is a good size for most types of divers.
A 4-inch dive knife isn’t too long that it becomes clunky during your dive, but is still a suitable size for most tasks.
The longer dive knives are best for experienced divers, technical divers and for waters where there is a lot of kelp.
Do you Really Need a Dive Knife Summary
To summarize, a dive knife is not mandatory but many divers prefer to carry one. A dive knife is an extra safety precaution that can release you from entanglements. The type of dive knife to choose depends on how you plan on using it and in what waters.
