History of Valves
Before early 70´s, drysuits was mainly used in commercial and military diving activities. To avoid discomfort created by squeeze at greater depth, overpressure valves were installed in the ankles, wrists and neck in order to remove excessive air inflated through the face mask. The inflation of gas also increased the undergarments insulation ability. This type of drysuit was named constant volume drysuit. The wetsuit was a great improvement and started to be popular in the early 50´s and drysuits in general became out aged.
Stig Insulán made his military service as a mine clearance diver. Stig was early involved in wetsuit and general diving gear manufacturing, which he started in 1962. With his dedication to diving and interest in design he tested the ideas during commercial diving operations.During long dives under ice in cold water Stig required something better.
Stig´s invention of the variable volume drysuit valve, opened up for a new era of underwater comfort.
From extensive diving experience and expertise in regards to diving physiology a number of criterias was set up:
1. It must act as an automatic overpressure valve, also at maximum setting.
2. It must have feature for manual dumping of insulation gas with occupied hands.
3. It must have a sensitive regulation of internal suit pressure.
4. It must at a given setting maintain internal gas for buoyancy control.
5. It must maintain insulation and flotation gas for prolonged surface time.
6. It must be placed on a location allowing easy gas dumping without inadvertently deflation. E.G Rising hands for alert call.
7. It must have adequate flow rate to enable easy ascent speed control.
8. It must be removable for checking and service.
9. It must be attached in a Valve Port, preventing leakage if material is compressed. Also to avoid rip out if tangled.
The result of Stig´s and SI TECH´s efforts is known worldwide and has evolved modern drysuit diving to what it is today!
History of Dry Glove Systems
The recreational use of drysuits increased, and the need for a simple connection of Dry gloves was emphasized. Stig Insulán developed a Quick Dry Glove System, where the diver could don and doff his gloves without any assistance.
The system allowed the use of an internal cuff seal, which eliminated the risk of suit flooding. Furthermore, the system allowed changing between high dexterity gloves and heavy rigid mitts, even when the diver was in the water!
History of new product names
New product names was introduced during 2011. Exhaust Valves was renamed after wrecks in Swedish waters and new products are/will be named accordingly.
Argo was a two-masted motorgaleas in oak, 94 tons gross, which sank south of Landsort on October 13, 1924. The ship was traveling from Lysekil to Islinge at Stockholm loaded with 140 tons of cobblestones.
Fog caused the accident, the fog signal of Öja came too late and the captain showed carelessness. He was quite confident that the sailing distance would be consistent with the logs, and according to the logs the ship would have been 12 nautical mil south of Öja. Argo was built in 1884 in Brixham, England.
Thetis was built in 1961 in Karlskrona, Sweden. She was a former research ship and was converted into a fishing boat in 1982. The ship was about 30 feet long and had a gross weight of 147 tonnes. Thetis sank October 24, 1985 on her way home from a fishing trip with a huge load of herring. The holds were filled to the brim and it is rumored that they even had herring in the engine room.
It was early in the morning and it was blowing hard, about 12-13 meters per second. They had for some reason chosen to go in the outer archipelago, instead of the calmer sea at Sotenäs Canal. Outside Tryggö, north of Smögen, Thetis suddenly got water over the deck during a heavy swell. The captain tried to counteract the heeling through sharp steer, but he did not manage to save the ship and it is now positioned at about 30 meters depth between Sotenäs and Tryggö, outside Smögen.
Gaude was a French cargo ship that was grounded and sank west of Viksten in 1919. The ship was traveling from Malmö to Stockholm and was carrying weapons and bayonets. Gaude was partly scrapped and the cargo was salvaged during 1919-1920. Gaude is now positioned at a depth of 23 meters.
Our Oval Dry Glove System is named after S/S ANTARES a German cargo ship that was torpedoed and sunk by the British submarine "Sunfish" on April 10, 1940.
SI TECH and its founder Stig Insulán has always had a strong foothold in the diving around Lysekil, not least about the accumulation of wrecks found in nearby waters. Over the years, many divers have asked Stig Insulán and later SI TECH for assistance in connection with diving on the wrecks in the area.
One of the reasons that SI TECH actually ended up in the vicinity of Lysekil area was just Stig´s contacts with the divers in Tång-Johan´s diving society who discovered the wreck of the ANTARES in 1965 and were the first to dive the wreck that year.