Navigating a ship safely requires constant situational awareness, particularly in environments with restricted visibility or high traffic. Traditional maritime navigation tools, such as radar, electronic chart displays (ECDIS), and automatic identification systems (AIS), provide critical information but require operators to synthesise data from multiple screens with different orientations. This cognitive demand increases the risk of misinterpretation, especially in complex or time-sensitive scenarios. To address these challenges, we present the design journey of the Maritime Head-Up Display (mHUD), an augmented bearing device that enhances navigational situation awareness. This is done by presenting information on an LED strip near the bridge windows, thereby integrating key visual information directly into the operator’s field of view. This provides intuitive, non-intrusive navigational assistance to the navigators while reducing cognitive workload and head-down time. Following a human-centred design (HCD) approach, we designed, developed, and evaluated multiple mHUD prototypes, ranging from conceptual scale models to full-scale installations, which were tested in simulators and onboard vessels. Our iterative process involved extensive feedback from navigators, shipowners, and maritime researchers, ensuring the system aligns with real-world operational needs. This paper outlines the research, design, prototyping, and evaluation phases of the mHUD, highlighting its potential to enhance maritime safety and efficiency. Our findings contribute to the broader discourse on human-computer interaction (HCI) in maritime contexts, offering insights into the integration of adaptive, embedded displays for enhanced decision-making in complex operational environments.