Surprisingly not much, it's not uncommon to be out there for days without seeing a boat. Nipigon is probably the best drive to fishery on the world, I think it's low traffic is due to the intimidating nature of the lake. It can go from glass to 6ft rollers quite fast. As Chuck noted above onamans is a great launching point. You can fish ombatika Bay and have some shelter around islands, the bay has extraordinary pike with fantastic walleye up by the jackfish River. Lake and brook trout not far from the onaman River outlet to the main lake