Your scuba diving knife can save your life underwater. Though knives are not mandatory components of diving gears and they are not made to protect you against large and dangerous creatures of the water, these special devices designed for being used underwater can help you solve potentially life-threatening situations such as getting entangled in seaweed, fishing nets or fishing lines, and can be used to grab the attention of other divers in your company in case you need help.
Dive knives are relatively small devices that are made from durable, lightweight and corrosion-resistant materials such as titanium or stainless steel and have a sharp edge that makes it suitable for cutting almost anything that can cause you trouble down under. To be able to attach the knife to your gear, you need a sheath for it – the best choice is a sheath with a retainer if you want to wear your knife on your buoyancy control device, or a strap, if you prefer to attach the knife to your arm or your leg. Some knifes come with a metal handle that can be used as a hammer – it is a very useful additional feature, but it makes the knife a bit larger.
Dive knives come in several different styles – here are the most common types:
Regular knives – these tools have a sharp edge for cutting and a serrated edge that doubles as a saw;
Dive shears – these devices look more like scissors;
Z-knives – knives with a cutting hook at the end;
Dive tools – knives ending in a prying tool.
The most important factor in determining the size of your knife is the place where you will be diving – if you will have to travel a lot to get there, small knives are more suitable. The style depends entirely on your personal preferences – all styles are suitable for freeing yourself from entanglements, so the best way to determine which one to buy is by trying out several styles to see which one fits your hand. Evaluate the grip of the knife – if you usually wear gloves during your dives, make sure you try the knife with your gloves on. Mount the scuba diving knife where you are planning to wear it, then try taking out the knife from its sheath and then put it back several times to see how comfortable it is to use it and how fast you can take it out in case of emergency.