In my day, pongos were army guys, it's what the navy guys called them. Navy guys were never pongos.
Actually - technically - the term was used at one time as a slang reference to any CAF member; it was predominate in this area with specific reference to the RCN I suspect because the Navy was always present here in far greater numbers than the army, whose presence was exemplified mainly by the PPCLI's, but in far fewer numbers than the navy. We conversely always associated 'pongo' with the navy probably for that reason. We kids used it in that context as did the adults most certainly.
At one time CFB Esquimalt had well north of 10,000 people at the base, military and civilian. The army even with the PPCLI battalion at Work Point, before it was shuffled off to Chilliwack in 1994 (and even later to Edmonton) and various reserve elements, was never ever as numerous.
Ironically even though the kids in my time (60's and 70's) and area (Gordon Head - Uvic - Mt Tolmie) always used pongo in reference to the navy - which in turn definitely, and unfairly, elicited a certain negative image of Esquimalt like few other things - I believe within the Forces' culture the army slang for RCN members was actually "squid". For my part that was a term I never ever heard or encountered anywhere until I was researching a DoD university project in the mid-80's. "Pongo" was, purely in my experience living all that way on the other side of the core from the base in the 60's and 70's, the de-facto default when speaking of the 'navy guys'.
Regardless its nice to see all the new local development on "this" side of the harbour, as the muni continues chugging along and evolving very nicely.