[Erik]

Welcome sir! If you're a confident swimmer then I'd say go for it in the rivers, depending on the river of course. Lots have terrible vis and you wont see anything, but some are clear and you'll do ok as far as hunting. I might be wrong, but I believe Walleye can't be taken by spear in BC. Colin (Amphibious) knows the DFO rules for BC really well, and hunts in rivers too.

nb: I'd recommend some non-river diving to get comfortable with the gear before getting into any moving waters.