Buyer's guide: Dive knives
A dive knife should be carried on every dive. Whilst most divers will probably not ever need to use it, it can be critical to free yourself from entanglement n fishing line or nets, or even kelp and algae. The most useful dive knives tick the following criteria:
- small enough not to cause entanglement
- sharp, cutting edge with serration to cut rope, kelp etc.
- a blunt tip is less likely to damage your equipment or yourself, leave the pointy tips for spear-fishermen
- possibly a notch for line cutting
- resistant to rust*
*Titanium is rust free, but better steel varieties such as H10 as used by Spyderco are corrosion resistant as well
It is imperative to take care of your tools, especially those which your life may depend on.
- Always rinse the knife in freshwater after diving in saltwater
- apply a light coat of vaseline or vegetable oil if the knife is not going to be used for a long time
There is no real need to have a large dive knife, a small, better quality knife is your best option.
You might want to consider to have some backup cutting device. These are ideally stored either in your drysuit-pockets or if small enough to be carried on your harness or webbing, this might be the best option. Examples include compact cutting devices such as the Benchmade Rescue Hook, EMS shears are another good option.
Also, you might want to consider a folding knife if it can provide easy one-handed operation, such as the Spyderco Atlantic Salt diving / rescue knife.
Another great choice is the Halcyon Titanium Dive knife, a very compact knife with good design and a very good sheath for mounting on the horizontal webbing of your harness:
