Last week we were talking about elements of the diving equipment that are not necessary for your baptism and one of them was the knife, but what is the use of a diving knife?

The diving knife is not a weapon, it is a tool, just like any of the knives in your kitchen. It is likely that you use the diving knife very rarely and surely none of them will be life-threatening situations for a diver … but it is very important that you carry a knife with you, and even two in the case of cave diving.

The main and most important use of the knife is to free yourself or your partner from being caught in a net. Although this may seem unlikely to you, just as many marine species fall prey to abandoned or active fishing nets, your fin, regulator or pressure gauge can also get caught, putting your life at risk. If that ever happens you will appreciate having a knife on hand. There are unfortunate cases, such as that of this diver from Seville, who died in October 2012 caught in one of these nets and the knife would have saved his life.

Although much less likely, it could also be the case of being trapped in thick underwater vegetation and then a few simple cuts would quickly free you.

The most common use divers use for the knife, also associated with fishing nets, is to release fauna. You can save the lives of species that fall into these nets like turtles with the help of a knife. If one day a situation like this presents itself to you and you do not carry this tool, you will not forgive yourself in life. In the following video you can see how divers who, with a simple diving knife, were able to alleviate from enormous suffering a whale shark that had dragged for years that net that cut off its skin.

Otro de los usos comunes es para avisar a tus compañeros de tu posición o de la presencia de algún elemento en el mar que merece ser tenido en cuenta. Pocos sonidos son tan reconocibles bajo el agua como el repiqueteo de filo o del mango del cuchillo cuando choca contra la botella.

Puedes llevarlo en la pierna, en el chaleco, puede estar hecho de titanio, de acero inoxidable, tener la punta roma o afilada, ser más largo o más corto, pero en cuanto empieces a bucear hazte con un cuchillo y llévalo siempre encima.

Another common use is to notify your colleagues of your position or the presence of an element in the sea that deserves to be taken into account. Few sounds are as recognizable under water as the clacking of the blade or the handle of the knife when it hits the bottle.

You can wear it on the leg, on the vest, it can be made of titanium, stainless steel, have a blunt or sharp point, be longer or shorter, but as soon as you start diving, get a knife and always carry it on you.

Types of diving knives

The first thing you have to think about is what type of diving you practice. You will not use the same knife (or the same number sometimes) if you are doing technical diving as if you are diving in caves or if it is a simple shallow dive. When you decide to buy a diving knife you will see, especially if it is the first time, that the options are much more than you thought.

One of the first considerations that you will have to do is regarding the shape and whether we want it with or without a point. Being pointed will probably bring you more problems than benefits. As we have discussed, the knife that is really used is to cut and having a sharp point can cause an involuntary puncture in the regulator, in the suit or on yourself. Sharp pointed knives are most often used for spearfishing. Another very interesting option is the scissors knife. If the diving knife is mainly used for cutting, why not use scissors?

When you go to the dive shop, or to any online material store, you will see that there are knives that have both sharp or smooth cutting edges … and even a serrated edge and a smooth edge. Choose the latter, with each edge of a style, since a single knife will serve you for different situations. When you need to cut a thick line or a branch you can use the serrated edge and when you need to cut a thin line or vegetation you will use the smooth edge.

An interesting feature that many knives bring is a shorter near the handle or the tip that will allow you to quickly cut nets and gills. Almost everyone already brings it, but it doesn’t hurt to notice.

As for size, when it comes to knives, not always bigger is better. The main thing is that it is comfortable and large enough for your hand to sit firmly on the grip. You will carry the knife safely on your leg (although there are more and more divers who prefer to put it in the jacket) and you have to feel comfortable. The knife, like the diving mask, the less you notice underwater the better.