Ilha Grande is a huge nature reserve so I was expecting a nature focussed trip. This was not the tour I was looking for. It was mostly a party on a boat with a big coach trip to get there and back.
Between all the hotel pickups and the admin at the port, it took 5 hours from pickup time to actually getting on the boat. 3.5 hours to get back.
The boat was pirate themed. It had a DJ and a big soundsystem with cheesy dance music and a bar in the middle. In the evening, you could go upstairs where it was quieter but there was no shade so not really a fun option through the day.
On the plus side, snorkeling with the fish in the lagoon was really beautiful. You should definitely pay the extra for the snorkelling kit (or bring your own). The guide was professional and spoke good English (although less clear if you went off script).
The main beach stop was super weird - there are two houses at the back of the beach with big fences to keep the tourists out so you are basically fenced on to the beach.
The food was basic but tasty - buffet with good salads, carbs, a couple of differen chicken stews and some fried fish. This is advertised as lunch but is actually about 4pm so make sure you bring snacks or pay for something to eat on the boat.