We are seeking a skilled and motivated Software Engineer to work on underwater communication systems with a focus on Physical, Datalink and Network protocol layers as part of their growing communication and simulation team. Recent proliferation of Unmanned Underwater Vehicles (UUVs) and the growing requirements for increased autonomy (in both the commercial and defence sectors) means that there is a need for secure underwater communication and acoustic networking infrastructure to fully realise the emerging robust, resilient and secure, subsea command, control, communication, computing and cybersecurity (C5) industry requirements. The role offers an exciting opportunity to work in a cross-layer development team to take forward and develop these emerging technologies and enable a new generation of secure, interoperable software and hardware solutions, aligned with both commercial and defence end-user requirements. Although focused on defence related areas the team will carefully leverage advances in both commercial and defence developments. The work will involve classified elements therefore requiring the successful candidate to be able to obtain UK security clearance (Secret). The developments will be steered by a Principal Engineer and a Technical Program manager. Working closely alongside others in the team, you will be responsible for implementing, testing and supporting acoustic protocol developments in this new family of products. Key Responsibilities: Drive the design, development, and implementation of new and emerging networking protocols for Layers 1-3, tailored to the challenging underwater domain (a high-latency, bandwidth-constrained environment that needs to be resilient to multipath and Doppler). Contribute to the definition and evolution of next-generation acoustic communication standards, enabling the development of secure, efficient, and cutting-edge technologies. Build high-performance, low-latency solutions optimized for real-time and mission-critical applications in dynamic and constrained settings. Develop robust, adaptive and scalable protocols capable of overcoming noise, interference, o and unpredictable conditions in environments such as wireless, satellite, and battlefield communications. Devise and execute test plans to evaluate protocol performance, reliability, and interoperability under extreme operating conditions. Develop, test, and deploy code using multiplatform build and dependency tools (e.g., CMake, Conan) and deployment pipelines that ensure cross-platform compatibility and efficient capability delivery. Ensure protocols meet stringent security requirements, implementing innovative techniques to protect sensitive data against emerging threats. Knowledge, Skills and Experience C - Able to write code from ground up, fix bugs and create basic features without assistance. Complex features and work may require assistance from Senior members. C++ - Skilled Understanding of object-oriented approach with a good understanding of the STL, encapsulation, inheritance, template parameterisation and other core language features. Experience of cross platform development is desirable. Electronics - Competent Can understand both analogue and digital circuits Documentation - Can record and communicate effectively in written form. Communication & Team Working - Can communicate and work effectively with other team members and members of other teams throughout engineering to achieve project deliverables. Qualifications 2:1 or above in relevant Engineering degree, such as Physics, Electronics, Mathematics.