The RS-790 is equipped with the R-700 balanced diaphragm first stage .
The membrane system isolates the internal mechanism from the ambient water, preventing salt, sand, chlorine and other contaminants from entering the internal mechanisms of the first stage. This helps reduce the risk of corrosion and mineral deposits and ensures more consistent regulator operation.
The first stage is equipped with a Dry Ambient Pressure Chamber . It helps reduce the effect of cold on the internal mechanism and is designed to operate in cold water below 10 °C . The additional ribbed construction improves heat transfer and helps reduce the risk of freezing.
The first tier includes:
High Flow LP connections allow for up to 15% higher airflow , providing additional air supply reserve during times of increased breathing demand.
The second stage is pneumatically balanced , so breathing characteristics remain stable across a wide range of diving conditions.
The balanced design of the second stage ensures a smooth and even air supply, while reducing breathing effort.
The second stage is equipped with a Venturi adjustment lever , which allows the diver to adjust the airflow characteristics.
This is especially useful during the different stages of diving – from entering the water to the dive itself.
The S-90 second stage is made using a lightweight composite body , so the regulator is not unnecessarily heavy and feels comfortable in your mouth.
The regulator comes with an ergonomically designed orthodontic silicone mouthpiece for more comfortable long-term use and less jaw fatigue.
TUSA RS-790 stands out:
The RS-790 is a particularly interesting choice for divers who dive in the cold conditions of the Baltic Sea, lakes or other cold waters . TUSA states in its official regulator guide that the RS-790 can be used to a depth of 50 m , and the minimum specified water temperature is 4 °C .
With a membrane first stage, dry environment pressure chamber and freeze protection, the RS-790 is designed to be suitable for more challenging cold water diving conditions.
The RS-790 is available with different first-stage connectors:
RS-790 INT (YOKE) – designed for cylinders with INT type valve.
RS-790 DIN – DIN version for use with DIN type cylinders. TUSA states that the DIN version is suitable for pressures up to 300 bar / 4350 psi .
| Parameter | TUSA RS-790 |
|---|---|
| First stage | R-700 |
| First stage type | Balanced membrane |
| Environmental isolation | Yes |
| Frost protection | Yes |
| Dry ambient pressure chamber | Yes |
| HP connectors | 2 |
| LP connectors | 4 |
| High Flow LP Connectors | 2 |
| Airflow through High Flow LP | Up to 15% higher |
| Second stage | S-90 |
| Second stage type | Pneumatically balanced |
| Venturi adjustment | Yes |
| Mouthpiece | Ergonomic silicone |
| Connection | INT or DIN |
| DIN working pressure | Up to 300 bar |
| Minimum TUSA specified water temperature | 4 °C |
| Maximum depth specified TUSA | 50 m |
| Nitrox | Up to 40%* |
* Nitrox compatibility up to 40% is specified in TUSA UK and other technical sources. When using breathing gases, it is essential to follow the manufacturer's instructions, the specific configuration and applicable diving standards.
The RS-790 is a regulator for divers who value a stable air supply, reliability, comfort and the ability to dive in cold water . A balanced diaphragm first stage, environmental isolation, freeze protection and pneumatically balanced second stage create a system adapted to more demanding diving conditions.
It is a versatile choice for both recreational and cold water diving when you want a higher-end regulator with great functionality and reliable TUSA construction.
