This charge goes towards managing and preserving the Great Barrier Reef. If you are prone to sea sickness take some medication prior to boarding the vessel. If you are not sure if you get seasick take some medication anyway. If you do get seasick don't worry, once you arrive at the reef it is calm and your motion sickness will generally go away. The best way to avoid sea sickness is to have a good breakfast, stay in the fresh air, look at the horizon and keep your mind busy.
Swimming also helps sea sickness to disappear quickly.