CNJ5 is the local Canadian designation for the water aerodrome (seaplane base) at Carey Lake west of Hearst, Ontario. There is an unpaved airstrip located adjacent with the designation CNX3. CNJ5 does not currently exist in the sim. CNX3 does exist, but has no associated infrastructure.
This implementation of CNJ5 only consists of a single water runway with starting points at which you can spawn. I could not find an existing runway designation, so I chose 16-34, which gives the greatest landing and takeoff distance. Of course, you can chose whichever direction works best according to the weather conditions.
Carey Lake is the home base for Hearst Air Service, which is an outfitter and charter company for fly-in hunting and fishing expeditions. I have implemented the aerodrome facilities, including hangars and float plane docks, in my CNX3 scenery located here (the CNX3 scenery is shown in the above screen shot). A fun adventure is to load up your float plane at CNX3 with a group of anglers and their gear, and fly out to Hillmer Outpost Camp (implemented here) or another wilderness destination.
Notes
To install the scenery, unzip and place the folder titled "mulberrywing-airport-cnj5-hearst-carey-water-aerodrome" in your community folder.