Part of the complexity of submarine design is that such needs are typified by extensive and densely engineered distributed ship service system(s) (DS3). Even though submarine early stage design is the phase to address major DS3 choices in the design process, in initial sizing and submarine synthesis reliance is often made on “past practice” and simple vessel displacement-based weight algorithms. Such an approach not only limits the ability of the concept designer to consider the impact of different DS3 options but also inhibits the opportunity (or necessity) to undertake Requirements Elucidation, specifically for DS3. One of the greatest challenges of DS3 synthesis is the development of the routing model of cables, ducting, and piping which can be time-consuming undertaken in Early Stage Ship Design (ESSD). Thus, this paper proposes a novel method for early stage routing of DS3 for a submarine. The approach uses network descriptions of the DS3 topology and computer-aided ship design (CASD) to produce DS3 routing rapidly in ESSD. The usefulness of the approach as an early stage design tool is demonstrated by using it to design the routing for various DS3 of a conventionally powered submarine.