handheld marine radios typically broadcast at 5-6 watts whereas a mounted unit will broadcast at 25 watts. antenna makes a big difference in your range.

We were there in August 2 years ago, no need to fish Canada side. We were on a houseboat too south of the narrows and fishing the reefs 20-30′. the group did well, lots of 22-24″ and slot fish too. Canada side is pretty but for us we didn’t so so well , only there for 4 hours. A chip for the GPS really cut down time to find and work the reefs.
like the man said, no livebait or alcohol.
you’ll have a blast