Tusa Imprex II Hyperdry Scuba Diving Snorkel

A classic open-top snorkel is a simple tube, the most reliable design, but it takes on water when a wave passes or you duck under. A semi-dry snorkel adds a splash guard at the top that deflects surface chop, though it still floods if fully submerged. A dry snorkel adds a float-operated valve that closes the top when submerged and keeps the tube mostly dry, at the cost of more moving parts and a little extra bulk and buoyancy.

A purge valve is a one-way valve in a sump below the mouthpiece that lets water you blow out drain away instead of sitting in the tube. It makes clearing easier, since a short sharp breath clears the snorkel with much less effort. The tradeoff is one more part that can foul with sand or grit, so rinse it and check that it seats cleanly.

Snorkels attach on the left side of the mask with a keeper that grips the mask strap, leaving your right side clear for the regulator hose. Position it so the mouthpiece reaches your mouth with the tube running alongside your head, without twisting the strap or pulling the mask skirt off its seal. Many keepers are quick-release, so you can remove the snorkel without disassembling the mask.

It depends on your training agency, the dive operation, and the diving you do, since some courses and operators require one. A snorkel lets you breathe at the surface without using tank gas, which matters on a long surface swim or in chop while waiting for the boat. Follow your instructor's or operator's requirements, and consider a folding snorkel if you want one stowed rather than on your mask.

A snorkel that is too long or too wide increases the volume of air you rebreathe and makes clearing harder, which is why recreational snorkels cluster around similar lengths and bore sizes. A flexible lower section lets the mouthpiece drop away from your face while you are breathing from the regulator. Mouthpiece comfort matters more than any other feature, so pick one you can hold without jaw fatigue.

Rinse the tube, mouthpiece, and purge valve in fresh water after each dive day, then let it drain and dry fully, because standing salt water in the sump grows mold. Check the mouthpiece for splits and the purge valve for trapped grit, both of which are inexpensive to replace. Store it out of direct sun so the silicone stays soft and clear.

The Hyperdry System keeps the snorkel's main tube dry by ejecting water through an independent escape pipe rather than back through the barrel. On the Imprex II, a special internal purge channel below the mouthpiece directs exhaled air upward and out the top while excess water is channeled down into a large capacity drain chamber and out the oval bottom purge valve, so less water sits at the mouthpiece between breaths.

It measures 16.9 inches by 4.8 inches (430 mm by 122 mm) and has an internal volume of 8.4 cubic inches, or 138 cc. Total weight is 5.5 ounces (156 grams).

The Imprex II Hyperdry is offered as Black (SP-580Q-BK), Black/Black with black silicone (SP-580QB-BK), Cobalt Blue (SP-580Q-CBL), Flash Yellow (SP-580Q-FY) and Translucent (SP-580Q-T). TUSA lists the same SKUs as Cable, Fluoro Yellow and Clear on its own site. The Black/Black SP-580QB version uses black silicone instead of clear crystal silicone.

TUSA lists it as suitable for all diving styles, so it covers both. For scuba, the crystal silicone flexible neck lets the mouthpiece drop away from your face while you breathe from the regulator, and the purge makes clearing easy after a descent. For surface snorkeling, the Hyperdry top and drain chamber limit how much water reaches your mouth.