Where to troll? One of the great things about trolling is its versatility. You can troll out in the ocean, on a lake, and even on a river. What matters is that the water is deep enough for a boat.Two things you’ve got to pay attention to when trying to find a good trolling spot. Number one, getting close to your fish. You can do this by either using a sonar to find schooling baitfish, looking out for birds swooping into the water, or tracking down floating weed lines.Number two, hitting the right depth.