Dive Gear

Hollis SD7 Flex Semi-dry

Wetsuits were invented in 1952, originally, wetsuits were made only with raw sheets of foam-rubber neoprene that did not have any backing material.  These old wetsuits were poor quality and not very durable. The later use of glue and heat-sealed tape made the wetsuit’s seams stiff and uncomfortable. Eventually wetsuits became lined with nylon to make them softer to the skin, but it also decreased the flexibility of the wetsuit. It took another 20 years or so for a solution was found: double- backed neoprene, sewed together. But the sewing resulted in punched holes and the sea water flushed through the seams of the wetsuit. To avoid this, the seams became the focus of development and resulted in better techniques in seam binding, including seam taping and seam gluing. The technology has changed considerably over the years.

old wetsuits

Diver John Foster wears Two of the early neoprene wetsuit prototypes, circa 1952.

When I started diving in the early 90’s, the farmer John, 2-piece 5mm wetsuit was the favoured wetsuit around Sydney. This was stiff, and compared to today’s wetsuits uncomfortable and on a thermal basis not very efficient.  When Abyss Scuba Diving opened in 2000 new higher stretch one-piece wetsuits started to come onto the market and today the vast majority of wetsuits are a result of that evolutions and the development of high flex neoprene.

This evolutionary process has at the same time led to the development of the Semi-dry suits. A Semi-dry suit is effectively a wetsuit with better-than-usual seals at wrist, neck, ankles and most importantly the zip. The seals limit the volume of water entering and leaving the suit. The wearer gets wet in a semi-dry suit but the water that enters is soon warmed up and does not leave the suit readily, so the wearer remains warm.

Hollis SD& Semi-dry

The Hollis SD7 Flex Semi-dry design makes it an exceptionally comfortable suit

The pinnacle of the evolution is the Hollis SD7 Flex Semi-dry. The Hollis SD7 Flex Semi-dry design makes it an exceptionally comfortable suit, functional and attractive. The Hollis  SD7 Flex Semi-dry is constructed from a 7mm compression resistant neoprene, combined with Supatex and high Stretch panels make this one of the most advanced Semi-dry’s on the market.  The SD7 comes with an improved TIZIP type zipper, longer than a  normal zip it ensures it is easier to wear and put on and take off. It is much more flexible and robust and is protected by a neoprene band that closes with Velcro, to minimize the flush through and to protect the zip whilst diving. The suit is overall made of super-elastic neoprene 7mm with new compounds patented by Hollis and combining but uses different thicknesses to achieve an unusual elasticity.

Some of the features that make the SD7 the the perfect wetsuit for diving around Sydney include :

SD& zip

The SD7 comes with an improved TIZIP type zipper


SD7 wrist seal

Extra long cuffs on sleeves and ankles to enable the fold for the perfect seal

Hollis SD7 Knee

Flexible and highly resistant knee protection, perfect for shore diving


SD7 zip pocket

Zip pocket on left leg with inner ring

Velcro Cargo pocket

Velcro Cargo pocket on the right leg

I firmly believe that diving is about enjoyment, and if you want to maximize that enjoyment then thermal protection plays an important part.  If you are wanting to enjoy diving around Sydney all year around then I strongly recommend that get yourself a semi-dry and that the Hollis SD7 Flex Semi-dry is the perfect suit for Sydney diving conditions.