While it certainly sounds cool, dive knives are not for fending off waves of sharks in the ocean.
Dive knives are for safety. There are several horror stories of divers becoming entangled in kelp or fishing line, and succumbing to the ocean. If these divers remained calm and came prepared with a cutting device, they may be here today to tell the tale.
Between all the different knife materials, lengths, tip types, brands, and more, it can be tricky to know what the best dive knife is for you.
As a PADI Divemaster who’s dove all around the world, from kelp forests in Monterrey, California to Florida shipwrecks covered in fishing line, I’ve learned what to look for in a dive cutting tool.
I’ve curated a list of the top five dive knives, and for what type of diver each is best for.
During my selection process, I focused on important factors such as:
- Blade material and edge retention for cutting performance
- Blade length and tip design for versatility and safety
- Handle design and grip for secure handling underwater
- Sheath type and attachment options for accessibility
- Corrosion resistance for saltwater environments
- Brand reputation and customer feedback
- And much more!
Below, I’ll review the knives, dive shears, and cutting tools in depth, and state for what type of diver and situation each underwater cutting tool is best for.
Then, we’ll go into a dive knife and cutting tool buying guide, followed by some frequently asked questions that come up when purchasing a knife.
Let’s cut to the chase!
Table of Contents
Best Scuba Diving Knives
- Best Overall Dive Knife: Cressi Skorpion
- Luxury Dive Knife: ScubaPro Mako
- Best Line Cutter: EEZYCut Trilobite
- Best Trauma Shears: Dive Rite Trauma Shears
Best Overall: Cressi Skorpion
Best for: Spearfishing, line, kelp | Blade Length: 4 ¾ inch blade | Blade Type: Serrated | Material: Stainless steel | Tip: Sharp | Weight: .5lbs | Sizes: S-XL | Pocket Style: Sheath
In my opinion, the best all-around dive knife is the Cressi Skorpion. The sharp point allows it to be used while spearfishing to dispatch fish, while the serrated topside and indent make it perfect for cutting line and kelp.
Both sides of the blade are easy to sharpen and its special coating helps the stainless steel resist corrosion from saltwater. It also comes with a snugly fitting sheath, which has a locking mechanism that you can release with one hand.
The handle is made from molded rubber and has a point on the end, which can function as a tank banging noise device underwater. It also has two long rubber straps for it to be attached to the arm or leg.
Pros:
- Budget friendly (you will lose dive knives!)
- Has serrated and smooth edge + line cutter
- Great for spearfishing
- Easy to sharpen
- Lightweight
- Tank banger on handle
Cons:
- Stainless steel will rust
- Sharp tip can be less safe
Luxury Titanium Pick: ScubaPro Mako
Best for: Spearfishing, line, kelp | Blade Length: 3.5 inches | Blade Type: Serrated + Sharp | Material: Titanium | Tip: Sharp | Weight: .5lbs | Pocket Style: Sheath
Next on the list, is the ScubaPro Mako. It’s a small, lightweight titanium knife, great for divers not on a budget. Titanium knives last a lot longer then steel knives, although as they don’t rust.
It features both smooth and serrated edges with a line-cutting notch. The Mako has a sharp tip but also somewhat blunted tip for versatility.
Its sheath has a secure push-button lock mechanism for safety and easily adjustable straps.
The handle is suitable for both left and right-handed people and the tip of the handle has a dual purpose as a metal tank banger and, more importantly a bottle opener.
Pros:
- Somewhat blunted tip
- Incredibly durable titanium
- Will not rust
- Serrated, smooth, and line cutter edges
Cons:
- Not budget friendly
- Titanium can be brittle, snap when braining a fish
Best Line Cutter: Eezycut Trilobite
Best for: Cutting Line | Blade Length: N/A | Blade Type: Guarded cutter | Material: Titanium | Tip: Blunted | Weight: .125lbs | Pocket Style: Velcro attachment
If you don’t already own a cutting tool for scuba diving, the EEZYCUT Trilobite is a great place to start.
It’s very affordable and can slice through the toughest of lines you’ll encounter when scuba diving.
Whilst its backward-facing, stainless steel blade poses no danger to fingers or hoses, it is designed to slice easily through the fishing lines, nets, and scuba webbing and can even cut through a drysuit if required.
It can’t cut anything thicker than 0.47 inches in thickness though, and it won’t be much use in difficult environments like kelp forests if you are diving in those.
Pros:
- Affordable
- Safe guarded vlade
- Lightweight
- Velcro attachment
Cons:
- Not suitable for kelp or fish
- Stainless steel will rust
Best Shears/Scissors: Diverite Trauma Shears
Best for: Cutting line, kelp, garments | Blade Length: N/A | Blade Type: Shears | Material: Stainless steel | Tip: Blunted | Weight: .15lbs | Pocket Style: Velcro attachment
You can get many different types of diving shears, some of which function as both knives and shears, the most effective and best scuba diving shears are actually simple Trauma Shears used by emergency responders around the world.
This strong, scissor-like tool will cut through nearly anything and comes in conveniently sized nylon pouches. The loops and straps mean they can be threaded onto a waistband or strap, looped through rings, or stored in a pocket.
Caring for these shears is especially important as it is easy for saltwater to get stuck in the mechanism and cause rust and corrosion.
Smooth movement is the key to shears, so be sure to rinse and dry them thoroughly after each use and consider using protective oil. Even so, expect to have to replace these more often than dive knives.
Pros:
- Affordable
- Safe guarded vlade
- Lightweight
- Velcro attachment
Cons:
- Not suitable for kelp or fish
- Stainless steel will rust
Dive Knife Buying Guide
Before purchasing a dive knife, you’ll first want to identify:
“Why am I buying a dive knife?”
In most cases, the tip or style of cutting device caters towards it’s purpose.
Sharp tips are ideal for spearfishers, as they will be able to dispatch fish easily, while also functioning as a line cutter.
Blunted tips make more sense if safety is a concern, and you don’t plan to use it for fish. Most blunted knives will have serrated edges and line cutting knotches.
Line cutters work best on fishing line, and are the most safety-conscious, as the blade is protected They’re also great for travel, as they are allowed into countries were carrying knives is prohibited.
Shears are more scissors than knife, and allow the cutting of straps, a thick netting, and even wetsuits/drysuits.
Knife Material
After determine your knifes purpose, it’s now time to take a look at materials. For the most part, you’re choosing between stainless steel and titanium.
Stainless steel will require regular sharpening and maintenance with oil to prevent corrosion from contact with salt water. Even if dive knives advertise a coating for stainless steel, it can still be scratched leaving it vulnerable to seawater.
Titanium blades are lighter, stronger, and require less maintenance and sharpening, but they are more expensive and harder to sharpen. Sharp point titanium knives can be brittle, and may not be a great spearfishing option, as they can break apart inside of the fish.
Dive Knife Handles
Metal handles are convenient for banging on your tank to get your buddy’s attention but are slippery and difficult to hold.
A well-designed ergonomic comfortable handle will make you much less likely to slip or drop it. Some also have added features like tank bangers or can be used as a hammer-like tools.
Knife Color
Thinking about the color of a diving knife might seem a little superficial but it’s an important consideration.
Whilst slick, black models look smart and are ideal for hunters (they blend in more), bright colors ensure that your knife can be seen when it’s most needed.
This could be when your buddy needs to grab it quickly, or when you’ve just dropped it on the seabed.
How to Attach a Dive Knife
Another important decision to consider when purchasing a dive knife, is how it will be carried or attached while diving.
The most common methods of attachment are:
BCD/Hose Mounted – A secure way to attach it to your gear, easy to access and not easily forgotten. Remember to clean and dry regularly, though. This is how I carry my knife as it’s easily accessible during my spearfishing trips.
Leg Mounted – These knives come with straps to attach to your calf or thigh. It has the benefit of quick access but it can get caught on things or fall out if it isn’t secure in the sheath.
Foldable knives – These can be stored in the BCD pocket, making them a great, safety-conscious choice. They can also be attached using a bungee or strap.
Frequently Asked Questions
What are the advantages of a good knife?
Titanium blades are less prone to rust than their stainless steel cousins. As a result, they require less maintenance and are lighter and stronger than stainless steel.
On the defense of stainless steel, it is also rust-resistant with the proper care and they are much cheaper.
What's the purpose of a dive knife?
Entanglements can be deadly because you’re relying on the gas you have left in your tank, and your (hopefully very close by) buddy to keep you alive. A bad entanglement can result in an out-of-air scenario.
This scenario works both ways, if your buddy finds himself entangled in a ghost net, you’re going to wish you’d bought that knife.
You can also use knives to have a positive environmental impact. Encountering a turtle with a net around its neck is incredibly sad and it’ll be even more heartbreaking if you don’t have a diving knife handy to help free it. They can also be used to safely remove lines and nets from reefs without disrupting the coral.
A good scuba diver must be a jack of all trades, and a good scuba diving knife allows him to be helpful in many different scenarios. In addition, some countries require divers to carry a knife as a safety precaution.
How do I look after my dive knife?
It is important to rinse your knife with fresh water if you have been diving in a saltwater environment. Ensure it is fully dry before storing it in its sheath. If there is dirt on the blade or handle, use mild soap to clean it before drying.
Sharpen the knife as needed, as you would a kitchen knife, by using a sharpening stone, steel, or worktop easy sharpener like this one.
For long-term storage, oiling the blade helps prevent rust. There are specific dive knife oils, but a thin layer of regular household oil like olive or canola will achieve a similar effect preventing moisture from reaching the metal.
Is Titanium Or Stainless Steel Better?
Reliability is the key here. You never know when you’ll need your knife so knowing you can rely on it when you need it is vital.
The best scuba diving knives are also strong and sharp and maintain their edge over time. Easy handling is also a key aspect of a good diving knife.
Getting your blade out quickly and knowing you’ll have a good grip when you do can be vitally important in time-sensitive situations.
Final Thoughts
Line cutters are the safest option and are often found unsheathed as the blade is protected. This is the best choice for those who travel a lot, especially into territories where knives are controlled. They’re also a great choice for beginners who may feel nervous about carrying an exposed blade around scuba gear.
Knives are best for confident scuba divers and are the most versatile choice. Avoid big, Rambo-style sea hunter knives and opt for a short, sturdy knife with a variety of features. Very long knives are harder to control and risk damaging your vital, and expensive, diving equipment.
Shears are a great backup choice, there’s a reason they are popular with EMTs and firefighters, they get the job done quickly and efficiently. Carrying a pair of diving shears as well as a knife is the combination of tools we recommend. Consider getting one or several of the cutting tools we discussed in this article to help protect yourself from an entanglement.
Which are you thinking of getting? Let us know in the comments. Safe Diving.
