Benchmade 18040S Undercurrent

The Benchmade 18040S Undercurrent is a robust fixed-blade knife for fishing and work on the water. The 109.8 mm sheepsfoot blade is in MagnaCut and partly serrated, so it can both cut cleanly and sever line and rope. The handle is Depth Blue Santoprene, the knife is 240 mm long and weighs 153 g, and it comes with a moulded sheath in Sonar Gray.

The Undercurrent is the heaviest-duty utility knife in the Benchmade Water series. Where the Fishcrafter is a thin fillet knife and the Intersect a compact knife for bait and small jobs, the Undercurrent is built for the rougher tasks on board: rope under tension, nets, lines and packaging. The S in the model number stands for the partly serrated blade, and the sheath with push-button lock can be mounted on your belt, pack or boat.

MagnaCut, serrated sheepsfoot and sheath with push-button lock

Five features that make the Undercurrent a work knife for life on the water:

• MagnaCut steel (60–62 HRC): Stainless powder steel developed without chromium carbides in its structure. It gives better corrosion resistance and toughness than S30V at the same hardness, and the steel is also relatively easy to resharpen.
• Modified 109.8 mm sheepsfoot blade: The spine curves down to a rounded point and the edge is almost straight. This gives control when you cut close to line, net or skin, and reduces the risk of cutting too deep.
• Partly serrated edge: The serrations bite into fibrous materials such as rope and braided line, even when they are wet and slippery, while the plain part of the edge handles precise cuts.
• 3.05 mm blade and Santoprene handle: The blade is noticeably heavier than the series' fillet knife, and the full 21.49 mm handle in rubbery Santoprene gives a secure grip with wet or cold hands. The knife is Ambidextrous.
• Moulded sheath with push-button lock: The Sonar Gray sheath holds the knife firmly until you press the button, and can be mounted on a belt, backpack or boat.

Maintenance and safety

• Rinse the knife in fresh water after use, wash it by hand and dry it thoroughly – a dishwasher can cause damage that Benchmade's warranty does not cover.
• Do not use the knife as a pry bar or screwdriver – not even the blunt sheepsfoot point, which is made for cutting, not prying.
• Always push the knife fully into the sheath so the push-button lock engages, and rinse salt and sand off the sheath too.
• Fixed-blade knives are often subject to stricter rules than folding knives – check the regulations in your country before transporting or carrying it in public.