The Snorkel Only tours with Silent World are typically around 3 hours, including 2 sites for 45 minutes each, which provides ample time to get out to the reef, have an extended period in the water to enjoy the sites, and return to the dock with plenty of time to relax and enjoy the rest of your day. Tours on the Scuba dive boat are  4 hours, including two sites for 1 hour at each location