icebob,
Here's my limited info on the Big Rideau. I have fished it 3 times once for lakers out of Portland in the south end where we pulled in 4 lakers in the morning of the opening day from 85-200' of water.
The other 2 times we have bass fished out of Rideau Ferry. There are tons of bays and islands to fish and we managed to catch a couple in the 4#+ range but predomintly were hitting 1.5-2.5 puonders. A good idea for bass is to fish jig n' pig in the huge weed mats. That's where the big ones are. Also give Adams lake a try. It is accessable from the Big Rideau and closest to the north end. Always bass in there.
I have also heard of decent sized pike and walleye but I have never targeted them so I have no info other than they do exist.
Hope this helps,
