It would be nice if you could consistently predict the depths to troll for salmon based on the time of year. However, on Georgian Bay, water temps vary based on a number of factors. I look for temps in the high 40's for salmon and low to mid 50's for rainbows. Winds can create pronounced changes in water temps. Early season salmon trolling demands a lot of patience. For example I have had significant success at Owen Sound just after ice-out trolling with the cannonballs very close to bottom over 160 feet of water. So there goes the general belief that the fish will be high in the water column. The very next day after west winds, we've done well running lead-core off the planer boards quite close to shore in 35 to 40 feet of water. The following week we can be off Collingwood in the little tinny very early in the morning flatlining AC Shiners off the planer boards well inside 20 feet of water and taking some very nice rainbows. Point is that change is constant on Georgian Bay and you should be prepared to adjust your set-ups in order to take fish.Ideally, it would be nice to have a two rod limit per angler so you could experiment with the riggers, divers and copper and lead-core rigs but I wouldn't hold my breath on the MNR changing the one rod per angler regulation. My boat was launched Friday at Hindson's but, like Canuck I'll not get too excited until late June for trolling for Salmon.