Dive knives and scissors come in a variety of designs to suit different needs and preferences. Here's an overview:

These are the most common type of diving knife. They feature a blade permanently attached to a handle, offering maximum strength and durability. Fixed blades are ideal for cutting through thick ropes, fishing lines, or even webbing in emergency situations.

• Pros: Stronger than folding knives, more reliable, easier to sharpen.
• Cons: Less portable due to their larger size, potential hazard if not properly secured.

Folding dive knives are a compact and convenient option for divers who prioritize portability. The blade folds into the handle when not in use, making them safer to carry. However, folding mechanisms can sometimes be less reliable than fixed blades under pressure.

• Pros: More portable, safer to carry.
• Cons: Less durable than fixed blades, potential mechanical failure during critical moments.

Serrated dive knives feature a blade with saw-like teeth. This design is excellent for cutting through tough materials like nylon or rope quickly and efficiently. However, serrations can make sharpening more difficult.

• Pros: Efficient at cutting rope and webbing, fast action.
• Cons: Difficult to sharpen, not ideal for fine tasks.

Dive scissors are specialized tools designed specifically for underwater use. They typically have blunt tips to prevent accidental injury, a robust build for strength, and ergonomic handles for comfortable grip even with gloves on. Scissors are invaluable for cutting fishing line or nets that may entangle you or marine life.

• Pros: Safer than knives (blunt tips), excellent for precision cuts, useful for freeing entangled marine creatures.
• Cons: Less effective at thick materials compared to dive knives.

These are premium options that offer exceptional durability and corrosion resistance thanks to their titanium construction. Titanium is a strong, lightweight metal perfect for underwater use where saltwater can quickly corrode traditional steel blades.

• Pros: Extremely durable, resistant to salt water corrosion, lightweight.
• Cons: More expensive than stainless steel knives.

Choosing the right dive knife or scissors involves considering several key features:

• Stainless Steel: The most common material for dive knives, offering a good balance of strength and affordability.
• Titanium: Excellent corrosion resistance and durability at a higher price point.
• Ceramic: Extremely sharp and resistant to rust but can be brittle and expensive.

Blade length typically ranges from 3-6 inches. A longer blade offers more cutting power, while shorter blades are more maneuverable in tight spaces. The shape of the blade (drop point, clip point, tanto) affects its utility for different tasks. Consider what you'll primarily be using your knife or scissors for when choosing a blade length and shape.

• Rubber/TPR: Provides excellent grip even with wet gloves, often textured for added security.
• Metal (Aluminum or Titanium): Durable but can become slippery when wet. Look for handles with knurling or other textures to improve grip.
• Plastic: Lightweight and affordable, but less durable than rubber or metal.

A good sheath is essential for safely carrying your dive knife or scissors underwater. Key features include:

• Secure Retention: The knife should be held firmly in place to prevent it from falling out accidentally.
• Quick Release Mechanism: Allows you to access your knife quickly when needed. Retention clips are common and often adjustable for different glove sizes.
• Drainage Holes: Allow water to drain from the sheath after use, preventing rust.

Folding dive knives should have a reliable locking mechanism to prevent accidental closure during use. Liner locks or frame locks are commonly used and generally considered safe options. Avoid automatic opening mechanisms as they can be dangerous underwater.

Dive knives and scissors offer numerous benefits for divers:

• Safety: A dive knife is your primary tool for self-defense in the water, allowing you to cut free from entanglement or fend off aggressive marine life.
• Utility: Useful for cutting rope, fishing line, nets, webbing, or other materials that may obstruct your progress or pose a hazard.
• Emergency Preparedness: Can be used to administer first aid (e.g., cutting clothing), start a fire, or signal for help in survival situations.
• Marine Life Rescue: Scissors are invaluable tools for freeing entangled marine creatures from fishing lines or nets without causing further harm.