There are many different things you can do while scuba diving but regardless of whether you like to ica dive pr simply want to take nice tropical fish pictures a dive knife is a recommended accessory. Since humans can’t breathe underwater something as trivial as getting entangled in stray fishing gear can be a life threatening situation if you’re not carrying the right safety equipment. When taking tropical fish pictures you may focus on the task at hand and miss a ghost net or other danger while pursuing a big grouper to get that price winning shot. If that happens you will be really happy that you brought along your trusted dive knife.

When it comes to scuba knives, two things are of imperative importance:

- Make sure that you get a scuba knife that is right for you and your diving style.

- Make sure that you know how to use the kind of dive knife you choose to get. If you don’t know how to use your dive knife correctly it can cause more bad than good.

Below you will find info on how to choose a knife that suits you.

Size matters

There are three main sizes of dive knives, big knives, mini knives and standard sized knives. A standard size dive knife, also known as medium size dive knife, has a 4-5 inch or 10-15 cm blade and is small enough to comfortably keep mounted on your leg, arm or BC. Make sure the handle is large enough for you to grip without much ado. Mini Knives are 2-3 inches (5-7.5 cm) and can be mounted on the air tube. Unfortunately, many of them come with handles that are difficult to grab underwater, especially when wearing diving gloves. Always test the handle prior to purchase. Any knife with a blade that is longer than 6 inches (15cm) is ti be considered big and can though to handle with any degree of precision under water. When scuba diving, big doesn’t automatically equals better so only get a big scuba knife if you know that you will be doing things underwater that actually require a big knife.

Material

Most dive knifes are made from titanium or stainless steel. Titanium knives tend to be the most expensive choice, but are on the other hand extremely resilient to rust and other types of corrosion and a good titanium knife will stay sharp for numerous dives. A stainless steel knife will on the other hand be more susceptible to rust and corrosion, but you can counteract this by rinsing it off in freshwater after each dive and leave it to dry completely before putting it back in its sheath. Coating it with a layer or oil or silicone is also recommended.

Should the knife have a serrated edge?

A serrated edge is ideal for cutting natural fibres such as hemp ropes and kelp, while a straight edge will be more apt at cutting artificial materials like nylon ropes and monofilament fishing lines. If you decide to go for a serrated knife, ideally pick one where the serrations run almost the entire length of the blade to make it possible to get a nice sawing motion going when you need to cut something. I recommend that you get a knife witha serrated edge on once said and a straight edge on the other, that way you get the best from both worlds.

Sharp tip or not?

Sharp tips are popular among spear fishers, but if you plan on using your knife for something else then a blunt tip is usually to be preferred. A sharp tip will easily break if you try to use your knife to hack, chisel, pry, dig or similar. A blunt tip is a lot less likely to end up damaging your scuba gear than a sharp tipped one.

Should I chose a knife with a cutting notch?

Yes, a cutting notch will make it much easier to cut small lines and other potential dangers.