Cruising the 1000 Islands is one of our favourite things to do. There are options; the Rockport Line is in the heart of the 1000 Island and also does an excursion to Boldt Castle (George Boldt is credited with the invention of the 1000 Island salad dressing – or his chef is!) Note: you will need passports to do Boldt Castle as it is in USA waters but it is not a big hassle.
Kingston 1000 Island cruise also has options including dinner, lunch and sightseeing (great options). There is also ‘K Pass’ available that combines various activities for cost savings.