IST

IST in South Africa

IST was founded in Taiwan in 1976 by three siblings, Irene, Stanley and Tony Lin, and the name comes from their initials. The company started out making windsurfing boards and moved into diving with boots, then masks, snorkels and fins. Its own catalogue now runs to regulators, BCDs and technical kit. In the shop it's mostly the masks, snorkels and accessories, chosen for fit.

Masks and snorkels

Start with the face, not the catalogue. The Martinique is a twin-lens mask shaped for medium to large faces, and the Martinique Narrow takes the same layout to slimmer faces, so a mask that lifts at the temples has a closer-fitting alternative. The Pi is a frameless single-lens mask with one wide window, the Imperial has a purge valve for clearing water hands free, and the Proteus comes with an anti-fog film already on its lenses. For breath-hold diving, the Hunter and Sonic keep internal volume low, which means less air to equalise on the way down. The Pro Ear seals each ear in its own cup, equalised through the mask. Compare them in dive masks and freediving masks, or see the Pegasus in full face masks.

Fitting a mask

Test the fit before the strap goes on. Push hair back off the forehead, hold the mask in place with the strap hanging loose and draw a little air in through the nose. A mask that suits the face stays on with no air leaking in at the edges. Check the nose pocket doesn't press on the bridge, and that the skirt sits clear of the eyebrows. Moustaches and stubble break the seal on most masks, so test the actual face that will dive. The strap belongs high on the crown, not over the ears, and it only needs to be firm: a tight strap folds the skirt and causes the leak it's meant to stop.

Buckles differ across the range. The Sonic, Pi and Proteus have buckles mounted on the skirt rather than the frame, and the Pi's push buttons loosen the strap while a pull tightens it. The Martinique uses quick-release buckles on the frame. The Sonic adds a deep nose pocket for pinching on the way down, and the Hunter folds flat to fit a BCD pocket as a spare.

Anti-fog lenses and mask care

The Proteus, and the anti-fog versions of the Hunter and Pro Ear, have a film on the inside of the lens. IST's instructions are the same for each: peel the matte protective layer off before first use, rinse before each dive, clean with fresh water only, and keep detergent, scratches and heat away from the film. Standard tempered glass lenses need a proper clean before first use and a defogger before each dive. The 30 ml IST Anti-Fog Spray is made from natural ingredients and suits masks and swimming goggles. After the dive, rinse the mask in fresh water, dry it out of the sun and keep it in its box, since a mask crushed in a kit bag tends to lose its shape at the skirt.

A torn strap is a small fix. The IST Silicone Mask Strap fits the Martinique, Martinique Narrow, Pi, Proteus, Hunter and Sonic, among others, with narrow ratchet ridges for fine adjustment. Find it in mask straps and covers.

Full face snorkelling

The Pegasus covers the eyes, nose and mouth in black silicone, with tempered glass lenses and a port at the mouth where a snorkel attaches. There's no mouthpiece to bite on, which suits snorkellers who find a mouthpiece tiring over a long swim. A multi-strap harness adjusts it to fit adults, and nose access lets the wearer pinch to equalise. It's a surface snorkelling mask.

Snorkels follow the same split. The Splash Guard snorkel has a guard at the top and a purge valve at the bottom for surface swimming, while the Apnea and the all-silicone Freediving snorkel have no valves to stick or leak, in snorkels. The Martinique mask and snorkel set, with a mesh bag, is in mask and snorkel combos.

The Splash Guard snorkel's silicone mouthpiece swivels through 360 degrees and the tube is PU, in five colourways. The Apnea comes in black, black and orange, and light grey. If the keeper on a Martinique set snorkel cracks, the IST Snorkel Holder is the maker's replacement for that snorkel.

Knives, bags and accessories

A BC knife sits where either hand can reach it. IST's run from the Black Mini, with a 7.2 cm 440C blade, to the 6-4 titanium BC knife, the Folding BC knife that packs down to 12 cm and the Knife Scissors for monofilament and net; the Dual Edge knife is made for spearfishing. Find them in knives and line cutters. The 81 cm Mesh Bag, the Mesh Duffel and the snorkel set mesh bag let wet kit drain on the way home, in mesh bags. Anti-fog spray is in mask defoggers, and neoprene repair cement and the 3 in 1 o-ring pick set are in maintenance and cleaning. For backplate divers there's the Tech BCD Weight Pocket and a harness leg strap, see weight and trim pockets, and alpha and diver down flags for the boat.

Knife details worth checking

Blade steel and mounting differ. The Black Mini has a 7.2 cm 440C blade with a G10 handle and is 13.8 cm overall. The Titanium BC knife is 15 cm overall with a serrated edge and line cutting groove, and its nylon sheath mounts upside down on a BC shoulder strap or stows in a pocket; handles come in black, blue and green. The Knife Scissors are 28 cm in 420 stainless steel and open at the handle into a pair of scissors. The Dual Edge spearfishing knife has an 11 cm needle point blade, a serrated section and a line notch, with a quick-release tab on the case. Rinse any knife and its sheath in fresh water after the dive, since salt trapped in a sheath works on the steel.

Bags for the trip home

Wet kit dries faster in mesh. The IST Mesh Bag is 81 cm long and 40 cm across, with a zippered front compartment for a logbook or keys, and it packs down as a spare bag for travel. The Mesh Duffel is 75 x 30 x 24 cm in 600D polyester with nylon mesh panels and grab handles, sized for fins, mask, boots and a wetsuit. The large snorkel set mesh bag closes with a drawstring and cord lock and takes a mask, snorkel and short fins.

Flags and repairs

IST's Alpha flag and diver down flag both measure 50 x 60 cm in nylon, with metal grommets and a 304 stainless steel stiffener that keeps the flag spread. The Alpha is the blue and white code flag A; the diver down flag is red with a white diagonal stripe. Find them in navigation and signals. IST's 30 ml neoprene repair cement comes in black and clear, repairs small punctures and tears, and also seals seams on neoprene to add strength.

Servicing at the Glenvista shop

IST's own catalogue includes regulators and BCDs. If you dive one, our servicing desk takes in regulators, BCDs, cylinders and dive computers from any brand and sends each job to the manufacturer's appointed agent. Most services take about two weeks. See gear servicing.