SEA has been awarded a contract by BAE Systems to deliver external communications systems (ECS) for integration into the UK Royal Navy's submarine fleet.
The £23m agreement, which involves detailed design and long-lead procurement, covers the initial part of the two-phased project.
SEA managing director Steve Hill said: "It is the culmination of fifteen years [of] hard work, often in close partnership with the Royal Navy.
"Our appointment demonstrates that the MoD (Ministry of Defence) policy to support procurement from small, innovative companies is paying off, bringing enhanced capabilities and reducing the cost of delivering an advanced and highly capable navy."
Based on open, modular and secure architecture with better remote control capabilities, the ECS is aimed at offering a complete-networked capability above and below the water.
SEA, which aims to replacing the navy's conventional end-to-end circuit technology, is expecting additional orders for integration next year.
BAE Systems Submarines Combat Systems director Paul Beavis said: "We have worked closely with SEA since the Astute-class competition and it's great to see this step-change in communications design being rolled out to operational submarines.
"With this open design, the evolution of submarines' communications now looks really exciting and we look forward to pulling through the emerging technologies that will keep submarines at the forefront of our defence capability well into the future."
Image: SEA will integrate external communications systems (ECS) on the UK Royal Navy's submarine fleet. Photo: courtesy of SEA.