Best Camera Trays & Arm Systems

Top-rated underwater camera trays and arm systems — modular designs, buoyancy considerations, and compatibility.

The arm system is the skeleton of your underwater photography rig — it connects lights and strobes to the camera housing in positions that create the lighting you want while remaining adjustable enough to reposition for different subjects and conditions during the dive. A well-designed arm system is rigid enough to hold position against current but flexible enough to reconfigure with one hand while maintaining buoyancy with the other.

System Components

A complete arm system consists of a tray (the baseplate that the housing sits on), arm segments (cylindrical tubes or ball-joint-connected sections that extend from the tray), clamps (devices that connect arm segments to each other and to the tray), and mounts (brackets that attach strobes or lights to the arm ends). Most systems are modular — you can add, remove, and rearrange segments to create configurations ranging from a compact macro setup (short arms, lights close to the housing) to a full wide-angle rig (long arms, lights positioned wide for maximum subject coverage).

Ball Joint vs Clamp Systems

Ball-joint arm systems (the dominant design in recreational and prosumer underwater photography) use spherical balls and clamp connectors that allow 360-degree rotation at every joint. This flexibility makes it easy to reposition lights quickly — loosen the clamp, rotate the arm, tighten. The trade-off is that ball-joint systems can loosen during a dive from the vibration of swimming and current, requiring periodic retightening. Premium ball-joint systems (Ultralight, INON, Nauticam) use precision-machined balls and clamps with strong locking mechanisms that resist loosening; budget systems use less precise components that require more frequent adjustment.

Loc-line arms (flexible, interlocking segments that hold position without clamps) offer an alternative for divers who want fixed lighting positions without the complexity of ball-joint adjustments. Loc-line holds its position once set — you bend it to the desired angle and it stays there until you physically move it again. The limitation is that Loc-line does not support heavy loads (large strobes) as rigidly as ball-joint systems, and the segments can creep under the weight of a heavy strobe during a long dive. Loc-line is best suited for compact cameras with small lights — not for DSLR housings with full-sized strobes.

Buoyancy Considerations

Your arm system adds significant weight and displacement to your camera rig — two aluminum arms, a tray, clamps, and two strobes can add three to five pounds to the rig's in-water weight. Positively buoyant arms (carbon fiber, syntactic foam) offset the weight of the rig and create a near-neutral or slightly negative system that is easy to carry and does not drag you down during the dive. Negatively buoyant arms (aluminum, stainless steel) create a heavy rig that requires effort to carry and can cause arm fatigue during long dives. For divers who shoot for the entire dive (sixty to ninety minutes of continuous rig handling), buoyancy-neutral or slightly negative arms reduce fatigue dramatically compared to significantly negative metal arms.

Float arms (arm segments with built-in positive buoyancy, typically achieved with syntactic foam cores) are an increasingly popular option that transform a heavy rig into a neutrally buoyant tool that hangs effortlessly in the water. The diver positions the rig in front of them and it stays in place — no effort required to support its weight. Float arms cost more than solid aluminum arms but provide a comfort improvement that photographers who use them universally describe as transformative — they wonder how they ever shot without them.

Travel-Friendly Arm Systems

Full arm systems are bulky and heavy to travel with. Several strategies minimize the travel burden. Compact arms (shorter segments, fewer joints) sacrifice maximum strobe spread for portability — an eight-inch arm instead of a twelve-inch arm packs more easily and provides adequate performance for travel photography where subjects are typically close range (reef macro, fish portraits). Quick-disconnect systems (arms that separate from the tray and from each other with ball-and-clamp connections) pack into smaller bags than fixed-arm systems — each component fits individually in padding rather than requiring a long, rigid case.

Dedicated underwater photography travel cases (Pelican cases with custom foam inserts, photography-specific rolling cases with divider systems) protect the housing, strobes, and arm system in a single package designed for airline transport. The case itself adds weight and bulk, but the protection justifies the overhead — a broken strobe or a flooded housing from baggage handling impact costs more than the case and its airline overweight fees combined. For divers who shoot on every trip, a dedicated photo travel case is an essential investment that protects thousands of dollars of equipment.

Compatibility and Future-Proofing

Arm system compatibility matters because most underwater photographers upgrade cameras and housings multiple times during their shooting career while retaining the same arm system, strobes, and lights. A well-chosen arm system should accommodate your current housing and any housing you might reasonably upgrade to in the next five to ten years. The critical compatibility point is the tray — it must match the housing's base dimensions and mounting hole pattern. Most trays accept a range of housing sizes through adjustable mounting brackets, but verify compatibility before purchasing. Some housing brands (Nauticam, Ikelite) produce their own arm systems optimized for their housings; third-party arm systems (Ultralight, INON, Stix) are designed for universal compatibility across brands. Investing in a universal arm system provides the most flexibility for future camera and housing upgrades — you replace the tray (the least expensive component) when you change housings, while retaining the arms, clamps, and ball mounts that represent the majority of the system's cost and utility.

Material Selection and Buoyancy Impact

Tray and arm material affects both weight and underwater handling characteristics. Aluminum trays and arms are the industry standard — lightweight in air, reasonably priced, and resistant to saltwater corrosion when anodized. The buoyancy penalty of a full aluminum tray-and-arm rig is typically one to three pounds negative, which adds to your total weight requirement and must be factored into your buoyancy check. Carbon fiber trays offer superior stiffness-to-weight ratio and are closer to neutral buoyancy, reducing the total system weight and the amount of additional lead needed to compensate. The cost premium over aluminum is substantial — a carbon fiber tray may cost three to five times more than an equivalent aluminum tray — but for photographers who already carry significant camera and housing weight, the reduced buoyancy penalty and better handling characteristics justify the investment. Plastic composite trays exist at the budget end of the market, offering the lightest weight and best buoyancy characteristics but sacrificing the rigidity needed to support heavy housings and powerful strobes without flexing under their own weight.

Arm Length and Configuration Strategy

Arm length determines how far your strobes or video lights sit from the camera lens axis — and this distance is the primary control for managing backscatter in underwater photography. Short arms (four to six inches) keep the rig compact and maneuverable but position the light source close to the lens axis, which illuminates suspended particles directly in the camera's field of view and creates the backscatter artifacts that ruin otherwise well-composed images. Longer arms (eight to twelve inches) move the light source to the side and above the lens axis, illuminating the subject from an angle that pushes scattered light away from the camera's field of view. The trade-off is maneuverability — long arms create a wider rig profile that catches current, makes maneuvering through wreck penetrations difficult, and increases the risk of contacting fragile marine life on busy reef dives. The practical compromise for most recreational photographers is eight-inch arm segments with ball-and-clamp joints that allow quick repositioning between wide-angle and macro configurations without changing arm length. Two eight-inch segments per side (connected by a clamp joint that adds an articulation point) provides roughly sixteen inches of total arm length with a mid-point fold for compact stowage during descent, ascent, and non-shooting segments of the dive.

Quick-Release Systems and Travel Considerations

For traveling photographers, the ability to disassemble a tray-and-arm system quickly into compact components is as important as underwater performance. Ball-and-clamp systems (the industry standard) allow full disassembly into individual arm segments, clamps, and tray in under two minutes, with each piece packing flat into a padded camera bag. The reassembly time is similarly fast, and the clamp joints provide infinite positioning angles — any clamp can be loosened, repositioned, and tightened at any angle without tools. The limitation of ball-and-clamp systems is that the clamp bolts can loosen during a dive from vibration and handling, especially plastic-bodied clamps used on budget systems. Stainless-steel clamp bolts with rubber-coated T-handles resist loosening better than plastic or aluminum hardware and allow tool-free tightening with wet gloves. Some premium systems use quick-release levers instead of threaded bolts — a lever arm locks the clamp in one motion and releases in another, eliminating the fumbling with threaded knobs that wet, cold, gloved hands struggle with on a rocking boat between dives.