Commercial diving contractors working offshore or across multiple project sites face a consistent challenge: how do you mobilise a complete, standards-compliant dive spread quickly, safely, and with minimal setup time on site? The containerised dive system exists to solve exactly that problem.
This article explains what a containerised dive system is, what the main configurations contain, how offshore and inshore variants differ, and which certification standards govern them. Whether you are specifying a system for an upcoming project or evaluating your first purchase, this guide covers the essentials.
What Is a Containerised Dive System?
A containerised dive system is a complete surface-supplied diving spread, or a key element of one, built within a standard shipping container footprint. The container is pre-fitted with life support equipment, control panels, gas management, and communications, creating a self contained unit that can be craned onto a vessel or platform and connected to power with minimal setup time.
Rather than assembling individual pieces of diving equipment on deck at each new location, a containerised system arrives as an integrated, tested unit. The equipment is mounted, plumbed, and wired inside the container during manufacture, so it is essentially plug-and-play on arrival. This approach dramatically reduces mobilisation time, which in commercial diving translates directly into vessel day-rate savings.
Systems are built within either a 10ft or 20ft container footprint. The choice of footprint depends on the operational scope, the number of divers being supported, and whether the container is required to accommodate a deck decompression chamber (DDC).
The Two Principal Container Types
A complete offshore dive spread typically uses two separate containers operating together: a dive control container and a machinery container. Smaller, simpler operations may use a single combined unit.
The Dive Control Container
The dive control container functions as the command centre for the diving operation. It is where the dive supervisor monitors and manages all life-support parameters for the divers in the water.
A typical 20ft dive control container configured for three-diver operations includes:
- A three-diver surface-supplied air control panel with individual depth gauges and gas management per diver
- A hard-wire diver communications system, such as an Amron three-diver radio panel, providing continuous voice contact with each diver
- Individual diver CCTV feeds, with monitors for live display and recording
- Oxygen and carbon dioxide analysers for atmosphere monitoring inside the decompression chamber
- A 60-inch twin-lock decompression chamber, complete with internal and external fit-out, enabling diver decompression and emergency recompression treatment on site
- A UPS (uninterruptible power supply) system to maintain chamber and panel operation in the event of a power interruption
- A dedicated breathing mask supply for the dive supervisor and chamber operator
- Umbilical management stands mounted on the container doors, with a penetration plate for clean external connection of diver umbilicals
The container is fitted with industrial HVAC to keep the supervisor operating in a controlled, quiet environment regardless of topside weather or noise conditions. This is a regulatory and practical requirement on offshore vessels, where open-deck conditions can be severe.
The Machinery Container
Where the dive control container is the operational nerve centre, the machinery container is the breathing-air engine room. It houses the compressor plant and gas storage that supplies both the dive panel and the decompression chamber.
A 20ft machinery container for a large offshore spread typically integrates:
- Two high-pressure compressors, such as Bauer units, for charging the high-pressure air bank
- One low-pressure compressor, such as a Quincy unit, for supplying LP breathing air directly to the dive panel
- Two independent 12 x 50-litre, 200-bar air racks: one dedicated to chamber supply and one to the dive panel, keeping these two critical systems isolated
- An integrated air management panel, stainless-steel plumbed to a penetration plate for clean external connection
- Forced exhaust fans, removable louvers, and dedicated intake filters for each compressor, ensuring safe airflow and equipment longevity
The separation of the machinery into its own container is deliberate. It keeps compressor noise and heat away from the supervisor, and it allows the two containers to be positioned independently on deck to suit vessel layout.
Inshore Alternative: Trailer-Mounted Systems
Not every operation requires an offshore-rated 20ft spread. Inshore commercial diving, covering harbour works, bridge inspections, marine civils, utility diving, and environmental operations, calls for a more compact and mobile solution.
For these applications, trailer-mounted dive control systems offer the same operational principles in a format that can be towed or driven directly to site.
A trailer-mounted inshore dive control unit is built to the same professional standard as a 10ft containerised cabin. It includes a two-diver air control panel with pneumo-fathometer gauges, integrated diver communications, operator seating, and a weatherproof cabin with ventilation and lighting. Optional upgrades include one- or two-diver CCTV systems. Because the unit is towable, it can be rapidly repositioned between sites without requiring crane handling or specialist transport, making it well suited to contractors who work across multiple inshore locations.
Certification: What the Standards Mean
Understanding the certification requirements for containerised dive systems is essential when specifying equipment for offshore projects. The certifications govern both the structural integrity of the container itself and the testing of the integrated equipment.
DNV 2.7-1: Offshore Container Lifting
Standard ISO shipping containers are engineered for stacked cargo transport, not for being craned from a pitching supply vessel onto an offshore platform in sea state conditions. DNV 2.7-1 is the certification that addresses this. It is a rigorous offshore container standard issued by DNV (formerly DNV GL) that specifies requirements for the structural design, pad eyes, lifting slings, and testing of offshore containers intended to be handled by crane offshore. A container built or modified to DNV 2.7-1 has been engineered and tested to withstand the dynamic forces of offshore crane lifts, protecting both the equipment inside and the personnel below. For any containerised dive system destined for offshore deployment, DNV 2.7-1 certification is a standard client and vessel operator requirement.
IMCA D023 and IMCA D018
IMCA D023 is the International Marine Contractors Association (IMCA) standard governing the design of containerised diving systems. It sets out requirements for the layout, equipment, and functional performance of a compliant system. IMCA D018 addresses the testing and certification of diving plant and equipment more broadly. Together, these two standards form the baseline compliance requirement for professionally supplied containerised diving systems operating under IMCA guidelines.
A compliant system will be delivered with a full FMEA (Failure Mode and Effects Analysis) and class-witnessed certification. The specific classification society varies by product and configuration.
A60 Fire Rating
Offshore oil and gas installations carry strict fire safety requirements. An A60 fire rating means the walls, floor, ceiling, and doors of the container are constructed to resist a severe hydrocarbon fire for 60 minutes without structural collapse or dangerous heat transfer to the interior. This rating is typically specified for containers sited on platforms or vessels where hydrocarbon fire risk is present. It ensures the dive supervisor and the life-support equipment inside can continue operating safely during a topside emergency, providing the time required to recover divers from the water.
When Do You Need a Containerised Dive System?
The decision to use a containerised system rather than assembling individual equipment on site comes down to four factors: mobilisation speed, operational scope, vessel or site constraints, and project compliance requirements.
- Offshore oil and gas: Vessel operators and offshore installation managers almost universally require containerised, certified dive spreads. The crane-lift capability of a DNV-certified container and the compliance of an IMCA D023 system are typically non-negotiable in project tender specifications.
- Offshore wind installation and maintenance: The offshore wind sector follows comparable standards to oil and gas for surface-supplied diving operations, with containerised spreads standard practice on installation and cable-lay vessels.
- Marine civil engineering: Projects such as harbour wall repairs, bridge pier inspections, and port infrastructure work increasingly specify containerised systems where the scope justifies the investment, particularly for multi-week campaigns where mobilisation time savings are significant.
- Salvage and subsea recovery: The flexibility of a containerised spread, which can be craned onto a salvage vessel at short notice, suits the rapid-response nature of salvage work.
- Inshore and civils contractors: For smaller, mobile inshore contractors, trailer and van-mounted systems provide the operational benefits of an integrated, compliant control station without the footprint or cost of a full offshore container spread.
Summary
A containerised dive system consolidates the core components of a surface-supplied diving spread into a pre-tested, transportable unit that can be mobilised globally via standard freight and placed on a vessel or platform in a single crane lift. The dive control container houses the supervisor station, communications, CCTV, decompression chamber, and gas analysis. The machinery container carries the compressor plant and gas storage. Inshore operations are served by trailer and van-mounted variants that deliver the same integrated control capability in a road-towable format.
