With a young child, if you want built in activities to keep him occupied, I would stick with companies that do Family Travel trips for river cruises. To my knowledge that is TB and ABD, though there could be more. You could always just book a river cruise on your own, but it will be almost all 65+ folks, no adventure guide, etc. Some river cruise companies don't even let kids sail. For the TB/ABD river cruises, those companies rent out the entire ship and the entire cruise is dedicated to the Family Trip, if that makes sense. One difference is you'll have 130+ people on the river cruise (split into smaller groups for excursions) and just your 20-40 on a land based trip.