There were several arguments about whether scuba divers really need a dive knife during their dive or not. Many people think that a dive knife has no purpose in Diving, other than making the wearer feel like an international spy. 

Another popular misconception is that scuba divers carry a dive knife to protect themselves against marine life and that is completely very far from the truth. 

Why Do You Need a Dive Knife? 

As a scuba diver, you will need a dive knife for two main reasons, including: 

• Aiding yourself or your dive buddy in emergency situations. 
• Helping free marine creatures. 

Aiding Yourself or Your Dive Buddy in Emergency Situations 

You will mainly need a dive knife to free yourself or your dive buddy in case of any entanglements while being underwater. A scuba diver getting caught in a fishing line is almostly common situation due to the ever increasing amount of fishing line, for example, that cost from a high-end spinecast reel or even net strewn around the blue ocean each day.

Most scuba divers that have experienced this situation and have successfully escaped from this predicament will never dive again without having a dive knife. 

For those who are diving in and around kelp forests, their possibility of getting entangled in sea kelp is very high and that is a very good reason for having a sharp dive knife in hand.

Helping Free Marine Creatures 

Several scuba divers have used their dive knives not only to free themselves, but also to help free marine creatures that have been trapped in stray fishing nets or lines.

You will also need a dive knife in heavy currents, as a dive knife in your hand can serve as a great anchor to the sea bed when there is a heavy current. That will help prevent you from drifting away when your hands can’t get a purchase on any outcrops or rocks. 

Although you may never find the need to use a dive knife underwater, you can simply use it as a good (tank-knocker) when you want to get your dive buddy’s attention underwater.

There is an argument that using a knife to saw away at a roop or fishing line underwater isn’t the most effective way to free yourself in an emergency and recently there are shears and line cutters that have been recommended over knives. 

Actually, they are both pretty cheap and can work better than a dive knife on a fishing line and a heavy rope. Eventually it’s always better to carry at least one form of cutting tool with you underwater, rather than be caught up in an emergency situation at which you wish you had one.