Open Box Dive Knives & Cutting Tools — Entanglement Insurance

A dive knife isn't a weapon and it isn't for prying. It exists for one situation: line, net, or kelp wrapped around you or your gear at a depth where you can't simply stand up and sort it out. Monofilament and discarded net are effectively invisible until you're in them, and they're present on most wrecks and a lot of reefs.

This collection covers knives, shears, and line cutters in various mounting styles. Every item is inspected and graded before listing; see Product Conditions for full definitions.

Knife, Shears, or Line Cutter?

• Knives — the versatile option. A serrated section handles rope and webbing; a straight edge handles monofilament. Blunt tips avoid puncturing a BCD or drysuit during use.
• Shears — often more effective than a knife on braided line and net, and safer to use with cold hands or thick gloves. Many technical divers prefer them.
• Line cutters — a recessed hook blade that cuts line without any exposed edge. Compact, safe to stow anywhere, and the fastest tool for monofilament specifically.

Carrying two cutting tools in different locations is standard practice in technical diving — if one arm is the entangled one, you need to reach a cutter with the other.

Blade Material

• Titanium — will not corrode in salt water, holds a reasonable edge, and needs essentially no maintenance. The low-hassle choice.
• Stainless steel — takes and holds a sharper edge than titanium, but will spot and rust without rinsing and drying after every dive.

Mounting and Access

A knife you can't reach is decoration. Traditional calf mounting is out of easy reach in an actual entanglement and can snag line itself. Most divers now mount cutting tools on the BCD waist strap, shoulder, or in a pocket — somewhere reachable with either hand while your other arm may be immobilised.

Check that the sheath's retention mechanism holds the knife securely but releases with one hand. A knife that comes loose during a dive is lost, and one that requires two hands to draw is useless when it matters.

Why Buy Open Box Knives from DiveCatalog.com?

• Inspected and graded — condition stated clearly on every listing
• Expert advice — our team can help you choose a tool and mounting position for your configuration
• Fast shipping — in-stock items ship within one business day
• 30-day returns — with RMA approval; see our Returns & Exchanges page
• Rewards program — earn points on every purchase

Frequently Asked Questions

Where should I mount a dive knife?

Somewhere you can reach with either hand — typically the BCD waist strap, shoulder, or a pocket. Calf mounting looks traditional but is hard to reach in an actual entanglement and can snag line itself.

Titanium or stainless steel?

Titanium if you'd rather not maintain it — it simply doesn't corrode. Stainless if you want a sharper edge and don't mind rinsing and drying it after every dive. Both work; titanium is more forgiving of neglect.

Why a blunt tip?

A pointed tip can puncture a BCD bladder, drysuit, or hose while you're cutting in an awkward position. Since a dive knife is for cutting rather than stabbing, the point offers little benefit and real risk.

Do I need more than one cutting tool?

In technical diving, yes — two tools in separate locations, so you can reach one regardless of which arm is entangled. For recreational diving, one accessible tool is generally considered adequate.

Do open box knives come with a warranty?

No. Open box and used products are not eligible for manufacturer warranty coverage.

Browse the full collection above, or see all Open Box & Used gear.