Halcyon Weighted Single Tank Adapter Review

Use: A year of diving
Current role: Fixed ballast in my single-tank backplate setup
Still in my kit: Yes

The Short Version

The weighted STA made my weighting cleaner and my trim more consistent by moving a significant portion of ballast off my hips and into a fixed position behind the backplate. It did not eliminate all of my trim weights, but the change was noticeable. The main frustration was the hardware: the permanently attached bolts were too long and pressed into my back. After I shortened them, the adapter worked well in my setup.

Would I buy it again? Yes. The functionality is excellent, but I would expect to address the bolt length again for my setup.

What Works

Moves ballast into a fixed position in line with my spine
Reduces the weight I carry around my hips
Makes holding trim easier in my configuration
Stable tank mounting with HP100s and AL80s
Stays out of the way once installed and fitted

What Doesn't

The supplied bolts were too long and pressed into my back
Permanently attached bolts required shortening rather than a simple swap
It did not eliminate the need for all trim weights

Why I Chose the Weighted STA

I follow the balanced-rig principle and typically dive a drysuit or thick wetsuit. I wanted to carry more of my ballast in a fixed, non-ditchable position instead of concentrating it around my hips.

My weighted STA adds 6 pounds behind the wing and backplate. Moving that weight up and in line with my spine made a noticeable difference in how easily I could hold trim. It reduced my hip-mounted weight without removing the need for every other trim weight.

The Bolt-Length Problem

The bolts supplied with my adapter were much too long for comfortable use and pressed into my back. Because they were permanently attached, I cut them down rather than replacing them with shorter hardware.

That modification resolved the discomfort in my setup. The adapter's function was good, but I would have preferred hardware that fit without that extra work. It is the part of the design I would most like to see reconsidered.

What It Is Like to Dive

Trim and Weight Placement: The centralized ballast improved the balance of my backplate setup and let me reduce hip-mounted weight. It made trim more consistent rather than removing the need to fine-tune the rest of my weighting.
Cylinders and Exposure Suits: I have used it with HP100s and AL80s in different exposure suits. Its mounting and buoyancy characteristics remained stable across those combinations without requiring reconfiguration of the adapter.
Movement and Control: It has not interfered with kicking or control. The tank stays aligned, the mount is secure, and the adapter stays out of the way.
Comfort After Fitting: Once I shortened the bolts, it was comfortable in my existing setup. There were no other compatibility problems, and I stopped needing to think about it during dives.

Ownership and Value

The construction has been rugged, and after dealing with the hardware I have not had ongoing maintenance demands from the adapter itself. It has done the specific job I bought it for without adding complexity to my dives.

It is not cheap, but the improvement in weight placement and trim justified the price for me. That value depends on actually needing fixed ballast in this position, not simply adding another component to the rig.

Who It Makes Sense For

It makes sense for backplate-and-wing divers who have a reason to centralize ballast and reduce hip-mounted weight. My experience is with a drysuit or thick wetsuit and a single-cylinder setup, where that fixed weight placement was useful.

I would choose something else if I did not want to deal with the hardware fitting my adapter required. An integrated-weight BCD without a need for an STA is also a different use case from the one I bought this for. The ballast is non-ditchable, which is part of the configuration decision rather than an incidental feature.