I have a friend visiting Toronto and I brought her to Centre Island. We were planning on renting those 4 people bicycles but since it was a summer weekend the day we went, there is an hour queue for those multiple people bicycles. Note: Get there early if you want to get one of those!
We ended up heading to the clothing optional beach to explore, since none of us have ever been to this kind of beaches. There are quite a number of people, and no, most people are not naked.
After all it was a fun walk around the island, and if you get off the ferry to the Centre Island, after your walk, you do not have to go back to the same dock you got off, we walked to Hanlan's point dock closer to the beach.