Travel to an Eastern Australia town such as Brisbane, Sidney or Forster. Make sure to travel in ideal dolphin swimming conditions, which usually occur between the months of May and October in Australia.
Contact one of the many cruise providers that offer a dolphin cruise, dolphin excursion or swimming with dolphins cruise. Examples of these providers include Swim With Dolphins, Dive Forster and Dolphin Wild.
Book a dolphin cruise and go out to sea with the cruise provider. The provider generally will rent out snorkeling gear such as a mask and wet suit, but if you have your own equipment you are allowed to bring it onboard.
Follow the instructions given to you by your travel guide, as these will help ensure your safety and the safety of the dolphins. Do not do anything to startle or scare the dolphins, such as making loud noises or sudden and violent movements.