The Hydrotank
Breathing gas is stored inside a bladder within the Hydrotank. Water enters or leaves the surrounding water chamber to change the total weight of the system.
Avelo in Sydney
Avelo Dive System: How It Works, Courses, Gear & Hire
A clear guide to Avelo’s water-based buoyancy system—what changes underwater, what still requires diver skill, and how to experience it with Abyss.
The short explanation
What is the Avelo Dive System?
Avelo replaces the conventional cylinder-and-BCD arrangement with an integrated system that controls buoyancy by taking in or releasing surrounding water. The water acts as ballast; it is not an air bubble that expands and compresses as depth changes.
The important point: Avelo does not hold your depth automatically. You remain responsible for every buoyancy adjustment, ascent, descent, breath and diving decision.
The system
How Avelo controls buoyancy
Avelo combines two core pieces of equipment, with an optional data layer on compatible dive computers.
The Jetpack
The backplate-and-harness assembly secures the system to the diver. Its battery-powered pump and controls let the diver add water or purge it.
Avelo Mode & Edge
Compatible computers can show in-dive information through Avelo Mode, while Avelo Edge provides post-dive performance analysis. These tools support awareness; they do not control buoyancy.
Add water
The Jetpack pump moves surrounding water into the Hydrotank, making the complete system heavier.
Set neutral buoyancy
Once the diver establishes neutral buoyancy, the incompressible water ballast remains much more stable as depth changes.
Release water
The diver purges water to make the system lighter, while controlling the ascent using the procedures learned during training.
For the manufacturer’s current component and compatibility information, see The Avelo System.
A practical comparison
Avelo versus conventional scuba
The biggest change is the medium used to manage buoyancy: water instead of an expandable pocket of air.
| Feature | Conventional scuba | Avelo |
|---|---|---|
| Buoyancy control | Add or vent gas from a BCD. | Pump water into the Hydrotank or purge it. |
| Response to depth | BCD gas compresses on descent and expands on ascent, so corrections are often needed. | Water ballast does not appreciably compress or expand, so the setting remains more stable across depth changes. |
| Core equipment | Cylinder, BCD or wing, harness and usually separate lead. | Hydrotank and Jetpack integrate the cylinder, buoyancy and harness functions; separate lead is often reduced, but individual weighting still matters. |
| Diver control | Manual. Good breathing, trim and awareness remain essential. | Also manual. Avelo stabilises a buoyancy setting; it does not select or hold a depth for you. |
Stable does not mean nothing ever changes
Your lungs, exposure suit, remaining breathing gas, equipment, body position, salinity and conditions can still affect buoyancy. Avelo removes the expanding BCD air cell from the equation; it does not remove the need for weighting, trim, breathing control or sound diving technique.
What divers may notice
The Avelo difference underwater and on shore
Fewer depth-related corrections
Once neutral, water ballast is not affected by pressure in the same way as air in a BCD. That can reduce repeated inflation and deflation during a dive.
A lighter, closer-fitting setup
The integrated configuration is designed to reduce land weight, separate lead and underwater drag. The exact difference depends on the tank, exposure protection and equipment being compared.
More attention available for the dive
When fewer adjustments are needed, some divers find it easier to focus on trim, breathing, their buddy and the environment around them.
Possible, not promised
Gas efficiency varies from diver to diver
Better trim, lower drag and reduced workload may help some divers use gas more efficiently. Avelo does not automatically reduce gas consumption or guarantee a longer dive. Depth, breathing, experience, exertion, temperature, conditions, no-decompression limits and the dive plan still determine when a dive ends.
Your Sydney pathway
Train, keep diving, then decide whether to own
Start by learning the operating procedures with an instructor. After certification, you can hire the system for more dives or explore ownership.
1. Complete the Avelo Dive Course
Avelo’s current conversion pathway for certified divers is called Avelo Essentials. Abyss lists its Sydney option as the Avelo Dive Course, combining online preparation, instructor-led system setup and two guided shore dives.
- Hydrotank and Jetpack supplied
- Regulator, weighting and dive computer supplied
- Current dates, price, eligibility and inclusions live on the course page
2. Hire an Avelo System
Build familiarity on more Sydney dives without buying immediately. Avelo rental is restricted to certified Avelo divers, and proof of certification is required.
View Avelo rental information3. Explore Avelo Gear
See the current Avelo system bundle and talk with the Abyss team about configuration, fit, training, service support and whether ownership suits your diving.
Shop Avelo gear4. Read Avelo Guides
Browse the Abyss Avelo article archive for practical perspectives, buoyancy background and the development of the system.
Browse Avelo articlesSee it in Sydney
Watch a diver experience Avelo at Kurnell
See Jess Hill’s first experience with the Avelo Dive System, then visit the course page when you are ready to try the controls with an instructor.
View the Sydney Avelo CourseTechnical references
Check the current source information
This page was checked against current Avelo, Shearwater and DAN information in August 2026. Use these sources for manufacturer updates, computer support and an independent overview.
Straight answers
Avelo Dive System FAQs
These answers cover the system, current Abyss pathway and the claims divers most often ask about.
What is the Avelo Dive System?
Avelo is an integrated scuba system built around the Hydrotank and Jetpack. It stores breathing gas and manages buoyancy in one architecture, using surrounding water as adjustable ballast instead of adding and venting air from a conventional BCD.
How does Avelo make a diver heavier or lighter?
The diver uses the Jetpack controls to pump water into the Hydrotank, making the complete system heavier, or to purge water, making it lighter. The diver selects and controls every adjustment.
Does Avelo hold my depth automatically?
No. Avelo is not an automatic buoyancy or depth-hold system. Water ballast remains stable across depth changes, but the diver must establish neutral buoyancy and control the dive using proper training, breathing, trim and awareness.
Does Avelo eliminate the BCD and all lead weights?
The Hydrotank and Jetpack replace the conventional BCD-and-cylinder architecture and are designed to reduce the need for separate lead. The exact weighting requirement still depends on the diver, exposure suit, water type and equipment, so a proper weight check remains essential.
Will Avelo reduce my gas use or let me stay down longer?
It may help some divers improve efficiency by reducing drag, workload and unnecessary buoyancy corrections, but no particular gas saving or dive duration can be guaranteed. Gas use depends on the diver, depth, breathing, trim, exertion, temperature and conditions.
Do I need special training to dive Avelo?
Yes. Divers need appropriate Avelo training before using the system independently. Avelo calls its current certified-diver conversion program Avelo Essentials; Abyss markets its local option as the Avelo Dive Course. Avelo rental through Abyss is limited to Avelo-certified divers.
Can a beginner learn to scuba dive on Avelo?
Avelo has an entry-level Avelo Diver pathway for people without a prior scuba certification. Abyss’s currently listed one-day Sydney Avelo course is a conversion pathway for certified divers. If you are starting from scratch, contact Abyss for the current beginner options.
Can I use my normal mask, fins, wetsuit and regulator?
Most personal gear, including mask, snorkel, fins, boots and exposure protection, remains familiar. The current Avelo System requires a compatible 300-bar DIN regulator. Abyss supplies the core Avelo system, regulator, weighting and dive computer for its listed course; check the course page for current inclusions.
What are Avelo Mode and Avelo Edge?
Avelo Mode displays compatible in-dive information on supported dive computers. Avelo Edge provides post-dive performance information such as stability, workload and efficiency. They are feedback tools, not automatic buoyancy controls. Check Avelo’s current compatibility list before buying a computer for this purpose.
What happens if the pump or battery stops working?
The water ballast already inside the Hydrotank does not suddenly change, so the existing buoyancy setting remains stable, and the mechanical purge remains available. Avelo training covers simulated malfunctions and the correct response. Follow your training and the current user manual rather than relying on a short website summary.
Is Avelo safer than a conventional BCD?
Avelo removes the large air pocket whose expansion and compression can contribute to rapid buoyancy changes in a conventional BCD. That is a meaningful design difference, but no equipment makes a dive automatically safe. Training, maintenance, weighting, monitoring, buddy procedures and controlled ascents remain essential.
Can I rent or buy Avelo equipment from Abyss?
Yes. Certified Avelo divers can view Abyss’s Avelo rental option, while the Avelo gear page shows the current retail range. Course availability, rental requirements, products and prices should always be confirmed on those destination pages.
About the dive centre
What divers say about Abyss Scuba Diving
These are reviews of Abyss Scuba Diving overall and may not refer specifically to the Avelo course.
Feel it for yourself
Ready to experience Avelo in Sydney?
The course is the best first step: learn the system, use the controls on two guided ocean dives, then decide whether hiring or ownership makes sense for you.
Dates, prices, eligibility, inclusions and availability are controlled by the linked course, rental and product pages.
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