Hero Polygon Knife

In spearfishing, a knife is primarily a safety tool. It can be used to cut shooting lines, nets, ropes, monofilament, or other items that may create dangerous situations underwater. It is also useful for handling the fish after the catch.

Often, yes. For most outings, a compact, well-sharpened knife is more than enough: the priority is that it is accessible, secure in its sheath, and truly effective at cutting.

In spearfishing, the compact size makes positioning and carrying easier, and it is absolutely adequate for dispatching small fish. However, when fish get larger, or when the risk of getting entangled in nets, lines, or debris on the bottom increases, a long, razor-sharp blade becomes an essential requirement.

Technical stainless steel offers good cutting performance, durability, and a balanced price. Titanium is more corrosion-resistant and very lightweight, but usually comes at a higher cost. The choice depends on how often you use it, your spearfishing environment, and the level of maintenance you want to dedicate to the knife.

For spearfishing, it is best to choose a compact, lightweight, corrosion-resistant knife that is easy to draw even with gloves on. The blade should be sturdy enough to cut shooting lines and ropes, but not so bulky that it interferes with finning and trim.

Yes. After every trip at sea, it is important to rinse the knife with fresh water, dry it thoroughly, and check the blade, sheath, and locking system. Even knives made from high-quality stainless steels generally contain a percentage of carbon that contributes to cutting performance, but can promote the appearance of slight oxidation if exposed to the saltwater environment for extended periods. For this reason, rinsing with fresh water is essential to limit oxide formation and preserve the knife’s efficiency over time. Even the most corrosion-resistant materials benefit from simple but regular maintenance.

The knife can be attached to the belt, arm, calf, backplate, or other points on your gear. The most important thing is that it stays secure, does not restrict movement, and can be reached quickly even in an awkward situation.