We are developing a low-cost autonomous underwater vehicle (AUV) for seabed inspection and survey in shallow waters. The design balances cost, manufacturability and operational performance by integrating coordinated mechanical, electrical and software choices. Key features include a low-cost sensor payload for autonomy; a propulsion and control layout that supports manoeuvrability and precise station keeping; a swappable battery system with an onboard battery management system (BMS) for safe, rapid turnarounds; and a compact electronics stack optimised for real-time control while minimising thermal and power overhead. The sensor and autonomy suite is tailored to shallow water conditions, combining IMU and depth sensing with cameras and low cost sonars to provide robust state estimation, obstacle detection and mapping in turbid or visually degraded environments. The project emphasises the use of off-the-shelf components and rapid prototyping to reduce unit cost and accelerate iteration, with the aim of evaluating the suitability of low-cost AUVs for cost-effective deployment in coastal monitoring, research and inspection applications.