The ‘island’ is an artificial offshore platform. The concept was originally conceived by Portugal’s Chief of Navy, Admiral Henrique Gouveia e Melo. A prototype was tested at the navy’s annual ‘REPMUS’ (Robotic Experimentation and Prototyping with Maritime Unmanned Systems) exercise, which took place off Troia, southern Portugal, across September.
Testing of the ‘island’ was conducted off the exercise’s main base – the navy’s Centre for Naval Operational Experimentation (CEOM), located on the landward side of the Troia peninsula in the Sado river estuary. The navy’s longer-term plan is to develop a larger ‘island’, to be located on the peninsula’s seaward side over the deep-water Setubal Canyon.
“The island is fully autonomous,” Lieutenant Commander Castro Veloso – CEOM’s head of information systems and communications, and the navy’s lead for developing the ‘island’ capability – told Naval News in an interview at CEOM, during ‘REPMUS’.
The prototype ‘island’ consists of a floating metal platform, fixed by four anchors, and accessed via a small, floating pontoon. The platform carries a standard, 20-foot ISO shipping container, which is divided into two sections, housing: a data processing centre; and a facility for divers, including space to store uncrewed underwater vehicles (UUVs).
The dedicated power supply onboard the ‘island’ is provided by solar panels, wind generators, and batteries, enabling the platform to be energy self-sufficient.
The platform’s standalone sensing capability includes a sonar system and other oceanographic sensors fitted underneath the platform: these gather acoustic, ocean current speed and direction, water salinity, and other data. The ‘island’ is also fitted with CCTV cameras, which can conduct ship classification and security monitoring.
Effectively, the ‘island’ can act as a forward base for sensors, extending detection range without increasing personnel risk.
Data collected onboard is processed in two ways: within the shipping container’s data section; or – primarily – using a data ‘hub’ fixed underneath the platform, within a special container to enable natural cooling by sea water.
Processed data is sent ashore via a seabed fibre-optic cable. Additional communications capability is provided through SATCOM connectivity and a 5G ‘bubble’ around the platform. The communications architecture enables operators ashore in CEOM and the exercise’s numerous commander task unit (CTU) facilities to access all the data from the island, said Lt Cdr Veloso.
For ‘REPMUS 24’, a key focus of the ‘island’ testing was to reduce the onboard data infrastructure’s power usage, Lt Cdr Veloso explained. For a data ‘hub’, as much as 70% of power can be expended on processor cooling: immersing the ‘hub’ in water for natural cooling is central to the concept’s aim of achieving energy self-sufficiency.
“One of the goals is for the ‘island’ to be truly self-sustainable …. Everything [onboard] is designed to be self-sustaining,” Lieutenant David Morgado, a Portuguese Navy media spokesperson, told Naval News in a visit onboard the ‘island’ during ‘REPMUS’.
The ‘island’ can also act as a forward base for uncrewed systems. UUVs and uncrewed surface vessels (USVs) have already operated from it.
For UUV operations, with communication difficult due to the nature of the underwater environment, the ‘island’ can enhance connectivity. UUVs can conduct missions, return close to the ‘island’, and use optical modems for sending and receiving information to and from the ‘island’ or connecting directly to its network. The data provided by the UUVs can then be transferred ashore via the cable or SATCOM links.
“With the support of the ‘island’, we can have a communications relay to navy facilities. We can have multiple platform types integrated, and we can have a better common operating picture.”
Lieutenant Commander Castro Veloso – CEOM’s head of information systems and communications
The ‘island’ also has deck space available. Lt Morgado explained that vertical take-off/landing (VTOL) uncrewed aerial vehicles (UAVs) could operate from it, supported by sensors like radar also fitted in this space. This would allow a radar to detect a target, with UAVs then deployed to locate and track it. Such capacity would enable the navy to train its decision-making, particularly in terms of taking rapid, first-response measures, said Lt Morgado.
A range of operational tasks can be conducted from the ‘island’, with these tasks reflected in ‘REPMUS’ serials. The seabed cable can be used for critical undersea infrastructure (CUI) security training. The diving facility in the shipping container can support diving operations, including UUV deployments. The ‘island’ itself can be used as a training target for surface and underwater harbour protection drills. Uncrewed system testing, including for mine counter-measures (MCM) or diving operations, can include interaction with the ‘island’ and its facilities, even if the uncrewed system is not deployed from the ‘island’, said Lt Cdr Veloso.
‘REPMUS’ testing also focused on identifying lessons for building the larger ‘island’, Lt Cdr Veloso explained. First, the navy needed to know that the underwater data ‘hub’ worked correctly. Second, the serials needed to prove that ‘hub’ power consumption was reduced through underwater cooling. Third, testing was designed to demonstrate that the power production, supply, and storage capability on the ‘island’ was sufficient and sustainable enough to enable effective operation of all the equipment onboard, including power sources, computer systems, data processing, and uncrewed system charging. The prototype is also being used to measure responses to changing sea states in terms of platform balance. One option could be to fit an auto-transition system to counter wave motions.
