Mares Horizon SCR – Frequently Asked Questions

20 Frequently Asked Questions About the Mares Horizon Semi-Closed Rebreather (SCR)

1. What is the Mares Horizon Semi-Closed Rebreather (SCR)?

The Mares Horizon SCR is an innovative semi-closed rebreather that recycles much of the gas you breathe instead of releasing it with every exhalation. Using Nitrox as its breathing gas, the system removes carbon dioxide and replaces the oxygen consumed during the dive. This provides longer dive times, quieter diving and improved gas efficiency compared with traditional open-circuit scuba equipment.

2. How does the Mares Horizon SCR work?

Unlike conventional scuba, where every breath is expelled into the water, the Horizon SCR continuously recirculates your breathing gas. Carbon dioxide is removed through a scrubber while fresh Nitrox is automatically added to maintain a safe breathing mixture. This makes diving more efficient and significantly reduces gas consumption.

3. What are the advantages of diving with a Mares Horizon SCR?

The Horizon SCR offers numerous benefits, including:

• Longer dive times

• Greater gas efficiency

• Warm, humid breathing gas

• Reduced bubble production

• Quieter underwater experience

• Less disturbance to marine life

• Comfortable breathing at all depths

• Reduced cylinder changes between dives

4. Who is the Mares Horizon SCR designed for?

The Horizon SCR is ideal for qualified recreational divers looking to expand their diving skills, photographers, videographers, wreck divers, marine life enthusiasts and extended range divers seeking longer underwater experiences.

5. Is the Mares Horizon SCR suitable for beginners?

Yes. Divers do not need previous rebreather experience. After meeting the course prerequisites, you can complete the SSI SCR Diver certification and safely learn to dive the Horizon under professional supervision.

6. Why is the Horizon SCR easier to learn than many other rebreathers?

The Horizon was specifically designed for recreational divers. Its intuitive controls, automatic calibration, simple pre-dive procedures and user-friendly electronics make it one of the easiest rebreathers available to learn and operate.

7. How much longer can I stay underwater?

Because the Horizon recycles breathing gas, divers typically enjoy substantially longer dive durations than with open-circuit scuba. Actual dive times depend on depth, gas mixture, breathing rate and environmental conditions.

8. Is breathing on a rebreather different?

Yes. Most divers describe the breathing as warm, smooth and natural. Because moisture is retained within the breathing loop, breathing is generally more comfortable than conventional scuba.

9. Why are there fewer bubbles when diving the Horizon?

The Horizon produces only a small stream of bubbles rather than the continuous exhaust seen with traditional scuba. This quieter operation allows divers to approach marine life more closely and enjoy a more peaceful underwater experience.

10. Is the Mares Horizon SCR safe?

When used correctly by trained and certified divers, the Horizon SCR is an extremely safe diving system. Like all life-support equipment, it requires proper training, pre-dive checks, routine maintenance and adherence to safe diving procedures. 

11. What training is required before diving the Horizon?

Divers must complete an approved SCR certification course, such as the SSI SCR Diver program. Training covers equipment assembly, gas planning, emergency procedures, maintenance, dive planning and safe operation of the rebreather.

12. What depth can I dive with the SSI SCR Diver certification?

SCR Diver certification qualifies divers to safely use the Mares Horizon SCR to a maximum depth of 30 metres within recreational diving limits.

13. Can I try the Mares Horizon before committing to a full course?

Absolutely. The SSI Try SCR Diving experience allows divers to experience the Horizon under the direct supervision of an instructor before deciding whether to complete the full certification course.

14. What gas does the Horizon SCR use?

The Horizon operates using Enriched Air Nitrox mixtures. Depending on the planned dive, different Nitrox blends may be used to maximise safety and efficiency.

15. What makes the Horizon SCR more affordable than fully closed-circuit rebreathers?

The Horizon has fewer complex systems than a fully closed-circ

uit rebreather, making it less expensive to purchase, easier to maintain and more economical to operate while still delivering many of the advantages of rebreather diving.

16. Does the Horizon have a dive computer?

Yes. The integrated dive controller continuously monitors the system, displaying depth, dive time, battery status and other critical information. It also assists divers during setup and throughout the dive.

17. Does the Horizon SCR require regular maintenance?

Yes. Like all scuba life-support equipment, the Horizon requires routine servicing, replacement of consumable components, proper cleaning and manufacturer-recommended maintenance to ensure reliable performance.

18. What types of diving are ideal for the Horizon SCR?

The Horizon excels in:

• Reef diving

• Wreck diving

• Underwater photography

• Marine life observation

• Extended recreational diving

• Scientific diving

• Dive travel

• Extended range recreational exploration

19. Why are underwater photographers choosing the Horizon?

Because it produces very few bubbles and much less noise than conventional scuba, photographers and videographers can approach marine life more closely, capture more natural behaviour and enjoy longer bottom times for the perfect shot.

20. Where can I learn to dive the Mares Horizon SCR?

Central Coast Divers offers both the SSI Try SCR Diving experience and the full SSI SCR Diver certification. Our experienced instructors provide comprehensive training using the Mares Horizon, giving you the skills and confidence to explore the underwater world in an entirely new way.

Whether you're looking for longer dives, quieter underwater exploration or the next step in your diving journey, the Mares Horizon SCR offers an exciting new dimension to recreational diving.

Discover the Future of Scuba Diving

Experience longer dives, quieter exploration and a completely new way of breathing underwater.

Book an SSI Try SCR Diving experience or enrol in the SCR Diver course today with Central Coast Divers and discover why more divers are making the move to rebreather diving.