We happen to book this trip last minute for our last day in Cairns with not much time so we booked half day trip. Was pretty much just the transfer over to Green Island where we could snorkel for couple hours and head back for our flight. Small island, just a resort there but also beautiful walking rainforest tracks, few snorkeling spots. Visibility kn day was great but low tide little tricky. Great pics, lots colourful fish. Not like outer reefs but still definitely worth it and a lot cheaper than 'whole day tour'. Trip each way only 45 min. Highly rec.👍