Engineering for the deep: Human support and rescue systems

DAVE THOMPSON, Unique Group 

As the global energy industry pushes into deeper and more remote marine environments, the demand for robust, compliant, and innovative subsea systems has never been greater. These systems must withstand extreme pressures while safeguarding human life in some of the harshest conditions on Earth. 

Unique Group has established itself at the forefront of this transition, delivering mission-critical projects that redefine subsea safety and life support. Known for its engineering ingenuity and global execution capabilities, the company has successfully delivered multiple high-profile projects that set new benchmarks for the offshore industry. Among them, the delivery of a DNV-compliant Human Support and Safety System (HSSS) for India’s first deep-sea manned submersible, MATSYA 6000, stands out as a groundbreaking achievement—positioning India as only the sixth nation with ultra-deep exploration capability, and cementing Unique Group’s role in advancing subsea engineering. 

This article explores the depth of innovation and engineering expertise that Unique Group has brought to three landmark subsea projects: the MATSYA 6000 HSSS in India, a Self-Propelled Hyperbaric Lifeboat (SPHL) for a European client, and a Hyperbaric Rescue Facility (HRF) for deployment in Angola. Each of these projects showcases how Unique Group delivers mission-critical systems for some of the world’s most challenging subsea environments, reflecting the company's ability to deliver precision-engineered solutions across geographies and sectors. 

CASE STUDY: DNV-COMPLIANT LIFE SUPPORT SYSTEM FOR INDIA’S FIRST 6,000-M MANNED SUBMERSIBLE  

Fig. 1. Matsya 6000, Human Support and Safety System built by Unique Group.

India’s Samudrayaan mission marked a turning point for the country’s marine science and subsea capability. As part of this historic initiative, the National Institute of Ocean Technology (NIOT), operating under India’s Ministry of Earth Sciences, aimed to develop a manned submersible capable of descending to a depth of 6,000 m below sea level. Known as MATSYA 6000 (Fig. 1), the submersible is designed to carry three personnel in a confined titanium sphere while maintaining atmospheric pressure inside the cabin. At such depths, the external pressure reaches 600 bar, presenting an engineering challenge that only a handful of nations have successfully overcome. 

The client’s requirements for the life support system were stringent. The solution had to be compact enough to fit inside a 2.1-m internal diameter personnel sphere, capable of delivering 12 hrs of full operational endurance and up to 96 hrs of emergency support. Given the environmental and spatial constraints, only a system with exceptional integration, miniaturization, and fail-safe redundancies could meet the mission's objectives. 

Unique Group's technical team worked closely with the NIOT team to design a fully customized and highly compact Human Support and Safety System. This included an oxygen supply unit, a carbon dioxide scrubbing system, dehumidification, a fire suppression unit, an environmental monitoring system, and an emergency breathing apparatus, all developed in-house and specifically adapted to the deep-sea application. Despite the challenges, the system was meticulously engineered to DNV standards and underwent rigorous testing. 

A full-scale prototype was built at Unique Group’s facility to validate design assumptions, optimize spatial layout, and ensure ease of operation. The Factory Acceptance Test (FAT) held in November 2024, witnessed by DNV surveyors, resulted in first-time certification—a rare accomplishment for a system of this complexity. Notably, the MATSYA 6000 HSSS was the first of its kind to be developed and certified for such a mission in India, representing a monumental leap forward in the country’s subsea ambitions. 

The impact of this innovation extends far beyond the Samudrayaan program. The compact and modular architecture of the HSSS allows for adaptation in various other domains, including military submersibles, commercial underwater research vessels, and even deep-sea tourism initiatives. This project has also been selected as a finalist for the "Innovation and Technology Project of the Year" Award by International Marine Contractors Association (IMCA) Awards 2025. Unique Group’s system sets a new benchmark in subsea human support design and validates its leadership in delivering high-stakes engineering solutions. 

CASE STUDY: SPHL WITH DAVIT SYSTEM 

While MATSYA 6000 demonstrates Unique Group’s ability to operate at the limits of underwater depth and pressure, the company’s portfolio also includes equally critical surface-launched systems that play key roles in diver evacuation and offshore safety. A prime example is the recently completed delivery of a 12-man Self-Propelled Hyperbaric Lifeboat (SPHL), with an integrated DNV-certified davit system, for a European client. 

This project was Unique Group’s first RINA-classed SPHL build, marking a significant milestone for the company. The lifeboat was engineered with autonomous propulsion, navigation, and life-support systems, capable of sustaining 12 personnel under pressure for 72 hrs. The unit was fully compliant with DNV, RINA, IMCA and ASME standards, featuring dual-side deployment via a certified davit system. The hyperbaric chamber was built to accommodate the under-pressure transfer of divers from a saturation diving system into the lifeboat in the event of an emergency. 

One of the key innovations of this project was its digital engineering model. The entire SPHL system was 3D-scanned to create a digital twin, which is now being used for training, maintenance planning, and quality assurance across future builds. This digital-first approach enhances traceability, improves documentation accuracy, and allows for remote diagnostics—a crucial advantage in offshore environments, where every second counts. 

Fig. 2. 12-man Hyperbaric Rescue Facility (HRF) and Life Support Package built by Unique Group for Oceaneering.

The success of the project and its timely delivery resulted in a follow-up order in December 2024, with another SPHL system scheduled for delivery in early 2026. More importantly, the SPHL project solidified Unique Group’s global manufacturing footprint, demonstrating its ability to deliver high-specification, safety-critical systems from multiple continents while maintaining consistency and quality across operations. 

CASE STUDY: 12-MAN HYPERBARIC RESCUE FACILITY (HRF) AND LIFE SUPPORT PACKAGE  

Unique Group’s third recent milestone project further illustrates its engineering versatility, this time through the delivery of a 12-man Hyperbaric Rescue Facility (HRF) and Life Support Package (Fig. 2) in support of Oceaneering’s diving operations in Angola. Designed to provide life-saving support for divers operating at depths of up to 300 meters, this HRF was developed with modularity, safety, and compliance at its core. 

The system included a DMAC-compliant twin-lock hyperbaric chamber mounted on a 40-ft DNV 2.7-1 certified skid, supported by two 20-ft containers housing the machinery room and control systems. This modular setup not only facilitates transportation and rapid deployment but also allows for future expansion or downgrading, depending on operational needs. The system was designed to integrate with SPHL mechanisms and included all necessary interconnecting hoses, cables and clamps. 

What set this HRF apart was its complete integration of environmental and life support systems with ergonomic comfort and usability. The main lock featured tiltable bunks, seating, a basin, and medical access, while the TUP lock was equipped with ablution, decontamination, and wet pot capabilities. This ensured that diver recovery and transition procedures could be executed safely and efficiently in high-stress conditions. 

Additionally, the machinery container was fitted with chillers, hot water units, potable water systems, and associated electrical reticulation, providing full self-sufficiency for extended offshore operations. The Angola HRF is a prime example of how high-quality engineering can be packaged into a mobile, adaptable format without sacrificing safety or performance. 

ENGINEERING SOLUTIONS FOR EVERY CHALLENGE 

Across all three projects, a consistent engineering philosophy emerges: enabling clients to operate safely, efficiently and sustainably in extreme environments. This philosophy extends beyond design and delivery to include compliance with DNV, RINA, IMCA, ASME, and DMAC standards, cross-border collaboration, and advanced digital engineering tools. 

Beyond diving and life support, Unique Group’s acquisition of Subsea Innovation has expanded its portfolio to include Emergency Pipeline Repair Systems, subsea clamps, riser hang-off systems, and back-deck mission equipment. By uniting diving systems, life support technologies, and subsea hardware under one umbrella, the company offers truly turnkey subsea solutions. 

Fig. 3. Controlled Mass Flow Excavation system.

Unique Group also helps operators reduce cost and carbon impact by offering subsea assets, such as Controlled Mass Flow Excavation systems (Fig. 3), lifting bags, and survey tools on a rental basis. This shared-use model extends equipment lifecycles, reduces waste, and ensures technology is deployed only when needed, aligning operations with both economic and environmental goals. 

The Group’s integrated solutions also extend to decommissioning and renewable energy projects. As the global energy sector transitions toward cleaner and more sustainable sources, offshore operations must balance legacy oil and gas obligations with the development of offshore wind, tidal, and subsea carbon capture systems. Unique Group supports operators across all stages—from development, installation and inspection to integrity management—bringing intelligence, precision engineering, and innovation to every phase of the subsea lifecycle. 

LOOKING AHEAD: EFFICIENCY, SAFETY AND SUSTAINABILITY 

In the future, the need for reliable, compact and compliant human support systems will only grow. As offshore industries transition into deeper waters and begin to intersect with emerging sectors such as carbon sequestration, renewable energy, and deep-sea mineral mining, the importance of safety-focused engineering becomes even more paramount. 

Unique Group is well-positioned to play a leading role in this future. With proven capabilities across ultra-deep, midwater, and surface-level support systems, and with production facilities and project teams spanning continents, the company is setting new standards for excellence in the subsea space. Their work on MATSYA 6000, the SPHL system in Europe, and the HRF in Angola are not isolated achievements. They are part of a broader movement toward engineering systems that are not only technically advanced but also ethically grounded in safety, sustainability and service. 

DAVE THOMPSON is the Group Engineering director at Unique Group, with over 30 years of experience leading engineering, technical and R&D teams across subsea, offshore, oil & gas, and renewable sectors. A results-driven leader, he excels in project delivery, capital equipment design, and developing innovative solutions that align with business and industry goals.