Begin your 1 hour and 45 minute tour with a jetty train journey 105 miles 17 kilometers across the ocean to visit the underwater observatory located the end of the end of the jetty descend 8 metres to the ocean floor via a spiral staircase to view some of the 300 species of vividly colored tropical and sub tropical corals sponges fish and invertebrates in their natural environment a unique design the observatory was opened in december 2003 and is one of only seven underwaterobservatori