Battle of the Titans: XDeep Stealth Tec, Hollis Katana 2, and Dive Rite Nomad Ray In-Depth Review

The XDeep Stealth Tec and the Hollis Katana 2 stand out as the two primary choices in today's sidemount BCD market. Both systems deliver exceptional performance across a wide range of diving environments and activities. Joining the fray in 2023, Dive Rite introduced the Nomad Ray to compete directly for this market share. This in-depth review will break down the key differences in specifications, performance, optional add-ons, and overall design to help sidemount divers decide which system best fits their specific needs.

Historical Background

XDeep Stealth Tec

In 2015, XDeep launched the Stealth Tec BCD, which rapidly gained popularity across the global sidemount diving community. This followed the massive success of the Stealth Classic (affectionately dubbed the "Pig's Stomach" by Kru Berm, which remains his primary go-to BCD through 2024–2026). The Classic, however, had a tendency to balloon up like a beach ball when carrying heavy loads and was slightly more cumbersome to don. These traits made it less appealing to sidemount divers utilizing heavy steel tanks or drysuits.

Originally, the minimalist Mexican-cave style design was optimized almost exclusively for aluminum cylinders. The engineering team behind the XDeep Stealth Tec successfully tackled this limitation by providing a wing with enough lift capacity for heavier steel tanks without allowing its profile to overly balloon.

Before this breakthrough, the Mexican style and the Florida-cave style designs existed in parallel universes that rarely crossed paths. Each side had geographic limitations and fundamentally different gear requirements. By bridging the gap between warm-water flexibility and cold-water demands, the XDeep Stealth Tec cemented its place as one of the finest sidemount BCDs in the world.

Hollis Katana 2

Hollis boasts a long-standing heritage in sidemount BCD engineering. Early models like the SMS100, SMS50, and SMS75 clearly reflected the brand's roots—heavy-duty, traditional Florida-cave style designs built for rugged environments.

In 2016, Hollis made its first real foray into the Mexican-cave style market with the original Katana 1. However, the release of the Hollis Katana 2 in 2020 marked a massive turning point. It was the first time since its debut that the XDeep Stealth Tec faced a truly worthy, head-to-head competitor.

Dive Rite Nomad Ray

Dive Rite is a true Florida heavyweight and a long-time rival of Hollis, renowned for producing incredibly durable gear. Their legacy was firmly established by the widely respected Nomad XT, followed by the Nomad LTZ and Nomad LS, which gradually adapted to the evolving demands of the Mexican-cave style market. Building on this reputation, Dive Rite launched the Nomad Ray in 2023. Stepping into the ring as a major contender, the Ray was designed specifically to reclaim territory long dominated by XDeep and Razor.

Technical Specifications Comparison

All three models are priced similarly within the same regional markets and offer highly comparable core functionalities. The key technical differences are broken down below:

Feature	XDeep Stealth Tec	Hollis Katana 2	Dive Rite Nomad Ray
Harness Style	Y-Shape	Adjustable: Can be configured as Y or H-shape	Y-Shape
Wing Lift Capacity	19 L / 42 lbs	18 L / 40 lbs	19 L / 42 lbs
Bungee System	Loop (6mm) – Comes as a 9m continuous cord to cut and custom-size	Loop (8mm) – Pre-installed from the factory	Loop (6mm) – 42 inches per side with a tool-less length adjustment system
BCD Weight	2.8 kg / 6.2 lbs	3.6 kg / 8 lbs	2.6 kg / 5.7 lbs
Primary Weight System	Spinal weight pocket spine (Velcro closure)	Spinal weight pocket spine (Velcro closure)	Integrated Internal Weight System (Zippered access inside the wing)
Weight Capacity	Multiple central pocket sizes available (3 / 6 / 10 / 12 kg)	Up to approx. 9.1 kg / 20 lbs	Up to approx. 6.8 kg / 15 lbs
Wing Material & Thickness	Ballistic Nylon 1100 Denier	Ballistic Nylon 1000 Denier	SuperFabric® outer armor, combined with 600D Nylon on the spine and 1000D Nylon on the body-facing side
Spine/Harness Fitting Adjustment	Adjustable via the webbing straps	Adjustable via Velcro (Quick Fit System)	Independently adjustable configuration (One Size Fits All)
Dual-Bladder Option	Available	Available	Available
Color Options	Highly customizable (Main panel, trim, side panels available in various colors) at an extra cost	Red/Black combo or Limited All-Black edition	5 stock factory colors (All-Black, Red, Blue, Pink, and OD Green) with no extra customization fee

Hardware Modularity and Customization

Sidemount diving inherently thrives on personalization and the flexibility to adjust a rig to an individual diver's precise needs. Regardless of which base system you choose, divers frequently purchase add-ons to streamline their setup—such as canister light mounting plates, rear utility pouches, and various hardware tweaks.

A great sidemount diver should thoroughly understand their equipment and modify it to suit their specific mission.

However, a glaring issue right out of the box with the XDeep is its inclusion of rubber O-rings on the waist strap to retain cylinders instead of proper metal low-profile D-rings. These rubber rings degrade over time and cannot reliably support heavy weight. Ultimately, most divers end up throwing them away immediately—or right after they snap—and buying aftermarket metal D-rings and hardware anyway. It feels like a useless placeholder that XDeep drops into the box.

For the fashion-forward divers, XDeep reigns supreme with its highly customizable colorways and custom name-embroidery options. Admittedly, these aesthetics have zero impact on the actual functionality or safety of the BCD. But hey, if you are looking for an orange wing with blue trim and your name embroidered on the back, and you don’t care about anything else—feel free to close this article right now and order a custom XDeep Stealth Tec through us!

Wing Design and Lift Profile

With a mere 1 kg (2 lbs) of lift variance between them, there is virtually no practical difference in buoyancy performance among the Stealth Tec, Dive Rite Nomad Ray, and Katana 2. A lift capacity of 40 to 42 lbs is more than enough to easily manage 5 to 6 standard aluminum cylinders simultaneously on a single dive. (Kru Berm notes that even a 35 lbs wing can comfortably handle 4 cylinders in seawater, though a higher lift capacity in freshwater environments definitely provides an added layer of psychological comfort and safety).

All three systems strategically cluster their buoyancy volume toward the lower portion of the wing. This design vastly improves surface floating characteristics and makes maintaining a perfectly flat horizontal trim underwater effortless.

Furthermore, while highly optimized for aluminum cylinders, these wings provide enough lifting power to handle heavy steel tanks, support extensive gear configurations for Full Trimix profiles, or handle deep, exploratory cave missions. They also adapt brilliantly to sidemount CCR (Rebreather) units. Both the XDeep Stealth Tec and Hollis Katana 2 are natively compatible with the K.I.S.S. Sidewinder CCR. In fact, the Hollis Katana 2 was co-designed by living cave diving legend Edd Sorensen, a prominent user of the Kiss Sidewinder system.

When looking at the upper-center portion of the wing—a high-wear zone when squeezing through tight spaces—the Dive Rite Nomad Ray utilizes its signature rugged SuperFabric®. Meanwhile, the XDeep Stealth Tec and Hollis Katana 2 employ reinforced heavy-duty nylon plates to safeguard against punctures and abrasions. Additionally, the wings on all three models expand outward and downward rather than bundling up directly on the center of the spine, resulting in a significantly cleaner, more hydrodynamic diving profile.

Dump Valves and Trim Mechanics

The positioning of the over-pressure/dump valves (OPVs) varies wildly across these rigs, making it one of the most critical deciding factors based on your personal diving style and habits.

• XDeep Stealth Tec: Features a single dump valve located at the bottom-center of the wing. This is the absolute lowest point where air naturally aggregates when in a flat trim position, allowing for highly efficient venting because the valve faces directly outward.

• Hollis Katana 2: Equipped with two dump valves. The first is tucked away on the inner side of the wing (facing the diver's body) on the left. The second sits at the base of the neck, operated via a pull-cord routed down the left shoulder strap.

• Dive Rite Nomad Ray: Also features two dump valves. The first is on the outer side of the wing on the left, and the second is a top-shoulder pull-dump routed down the left shoulder strap.

The Shoulder OPV Debate

The inclusion of a shoulder-mounted dump valve is a direct legacy of the traditional Florida-style design (as seen on the older Dive Rite Nomad XT). Divers transitioning from standard backmount jacket BCDs often appreciate this feature because it allows them to dump air instinctively from an upright position, regardless of their trim.

Furthermore, Edd Sorensen added the shoulder pull-dump to the Katana 2 specifically for K.I.S.S. Sidewinder CCR divers. When using that rebreather, the scrubber canisters sit directly over the upper rear flanks of the cylinders, which can completely block a diver's ability to reach back and pull a traditional lower-rear dump valve. (Some divers on non-shoulder systems have to resort to rigging custom pull-strings routed through their crotch strap just to access their lower valve). Dive Rite has consistently embraced this, maintaining a shoulder OPV across their entire lineage from the Nomad XT, LTZ, and LS right through to the modern Nomad Ray.

From a broader technical perspective, a shoulder OPV is highly versatile. It accommodates various rigging methodologies, including the Toddy Style sidemount setup. If you completely dislike it, it can easily be blanked off using a standard low-profile plug.

What many divers overlook is that having multiple dump valves allows for far more rapid buoyancy adjustments compared to a single-valve system. Additionally, if you have limited shoulder mobility due to wearing a thick wetsuit or a heavy drysuit, a shoulder pull-dump can be an absolute lifesaver.

Hidden vs. Exposed Valves

The Katana 2's decision to hide the lower OPV behind the wing fabric serves a clear purpose: it shields the valve from direct impacts against overhead environments. An exposed, protruding valve can become an entanglement hazard or a catastrophic buoyancy loss hazard if sheared off. This protective fabric-flap approach is highly respected and utilized by several other technical brands, such as Hot Dive (Manta), Tecline (SIDE16 Avenger), Apeks (WSX), and Mares (XR Sidemount).

Buoyancy Effects on Trim & Emergency Management

Mexican-style systems store a massive percentage of their air volume right around the waist and lower back. This buoyancy bubble naturally works to keep the diver in a "legs-up" trim.

However, if an emergency strikes—such as a Low-Pressure Inflator (LPI) free-flow—air rushes into the lower bladder instantly. This can aggressively rotate an unprepared diver into an inverted, head-down position, causing a violent, feet-first runaway ascent.

Because every BCD mentioned in this review features a lower dump valve, executing an emergency dump to prevent a runaway ascent is possible on all of them. The caveat here lies with the Hollis Katana 2: because its lower valve is hidden on the inner side of the wing, locating and pulling it in a high-stress, inverted scenario requires muscle memory and dedicated practice. This highlights the absolute necessity of mastering your specific kit. Ultimately, keeping your inflator components pristine and serviced regularly to prevent an LPI free-flow in the first place remains your best line of defense.

Harness Fit and Ease of Adjustment

All three models deliver an excellent, user-friendly adjustment experience. They allow you to adjust individual straps one at a time. This is a massive upgrade over rigid "single-webbing" continuous loop harnesses (like the Razor or older Dive Rite LS systems), where shifting a single point throws off the geometry of the entire rig, requiring expert fitting or expensive professional adjustment fees. (Rest assured, if you purchase through us, your custom fitting is completely free).

The Hollis Katana 2 holds a slight edge here thanks to its Quick Fit System. This Velcro-based spinal adjustment setup makes resizing the harness height slightly faster. However, unless you are using the BCD as a commercial rental unit, harness fitting is a "set-it-and-forget-it" process. Whether you choose XDeep, Hollis, or Dive Rite, expect to spend an identical 15 to 30 minutes initially to dial in your perfect personal fit.

When it comes to weight distribution, all three rigs center their primary ballast along the spine.

The Dive Rite Nomad Ray, however, requires you to unzip the inner wing fabric to access the weight slots. While this takes a moment longer during initial setup, it does not add any significant delay to your pre-dive prep. If you need to add trim weights elsewhere on any of these rigs, a simple slide-on weight keeper modification onto the harness webbing does the trick perfectly.

Bungee Thickness: Why It Matters

The bungee system is the heartbeat of any sidemount rig; it is what keeps your cylinder valves tucked tightly into your armpits.

Hollis ships the Katana 2 with heavy-duty 8mm bungees, which are exceptionally durable and optimized for heavy steel tanks. However, divers who primarily use aluminum tanks often complain about this out of the box, as 8mm can feel overly stiff and cumbersome, leading many to immediately swap them out.

To look at it objectively: if XDeep buyers have to spend extra money replacing rubber O-rings with metal D-rings, Hollis buyers swapping out 8mm bungee for 6mm bungee will actually find it much cheaper and easier to do.

Meanwhile, the Dive Rite Nomad Ray eliminates this headache entirely. It features an incredibly elegant, tool-less adjustment system using mid-weight bungees. You simply pull the bungee cord to your desired tension, tie a simple knot, and tuck the excess away neatly inside a dedicated fabric sleeve on the wing edge. It is completely hassle-free. Of course, if your specific diving style demands a continuous loop bungee configuration, any of these systems can be slightly modified to accommodate that preference.

Conclusion: Has the King Been Dethroned?

The introduction of the Hollis Katana 2 and the Dive Rite Nomad Ray has effectively shaken the XDeep Stealth Tec from its uncontested throne. Both challengers have performed brilliantly, offering near-parity across almost every technical metric.

Truthfully, once a diver puts in the hours to truly know and configure any of these three BCDs properly, they will all deliver flawless, elite-level utility underwater. This rivalry is an absolute win for the consumer, bringing much-needed diversity to the sidemount market.

Your final purchasing decision will likely come down to nuances: personal aesthetic preferences, price point variations within your local region, or highly specific mission requirements (such as matching a rebreather or requiring maximum travel portability).

Ready to take the next step? Whether you are looking to get certified in Recreational Sidemount, XR Technical Sidemount, or advanced Technical Tri-Mix Diving, get in touch with us today for expert consulting, gear fitting, and world-class training!