It is an unfortunate fact that many divers do not carry a dive knife; but these are necessary tools, not weapons and should be carried, safely sheathed, on every dive so that you are equipped for the unexpected event when it might just save your life!
The occasion when you are likely to need to use a diving knife is extremely unlikely to be a ‘James Bond’ type situation where you are required to use a huge knife to fight off ‘baddies’, a marauding shark or extricate yourself from some other life-threatening situation. In fact, the most likely time you will need one is to cut through something as seemingly innocuous as entangling monofilament fishing line or thick strands of seaweed!
Dive knives come with different options – so for a good, multi-purpose diving knife, choose one that has:
- A Sheath. This needs to fix securely to your body and hold the knife safely in place but allow it to be removed from the sheath and replaced safely using only one hand.
- A double-sided blade. One edge should be smooth for slicing, the other edge serrated for sawing.
- A sharp edge! That may sound obvious, but choosing a knife made from hard metal such as Titanium that will keep its edge is probably better than choosing a soft steel blade that needs re-sharpening.
- A metal handle or a hammer tip on the butt end. The purpose of this is so that you can attract your diving buddy’s attention by tapping on the tank of your (or their) scuba equipment.
- A sensibly sized blade! Huge dive knives are available, with blades of around 9″. In practice, these are difficult to use – and for a novice diver, especially, there is a greater risk of injury. A blade of around 4″ – 5″ is probably the best size for all-around efficiency and general use.
- A Blunt Tip. If you ever come across a giant Great White while diving, you might be sorry you took this advice – but for the other 99.99% of the time, you will be much safer with a dive knife that does not have a sharp point! The blunt tip knives are also more useful for other tasks like prying something loose or for using as a screwdriver – both are jobs you are more likely to need to do on a regular basis than to fight off sharks!
What Other Features Are Available
Zip Diving Knife: For wreck diving, Zip knives are a useful tool. These are also called Z knives and are generally used in addition to a larger dive knife as the purpose of their hooked design, rather like a claw or talon, is to cut through the type of monofilament line that can entangle a diver.
Dive Shears: Dive shears are becoming increasingly popular. They are safer to use and multi-purpose. These can be used like scissors with an opening and closing action of the handles. Used closed, they perform like a knife, with a blade on the outside edge. Shears are also less likely to cause you legal problems when traveling, although obviously, your diving knife should never be in your hand luggage when traveling by air.