Ryan Tate is Sam's co-worker and a geologist. When Cleo shows him the magnetic rock from Mako Island, he becomes very interested in it. With his help, the girls know what the Mako Island really is. Because of Kim, Ryan goes to Mako Island and he discovers the Moon Pool. Samantha refuses to let Ryan go to Mako Island and tells him to again work at lab. He also gives Cleo a telescope in the episode "Beach Party." During the end of the season, Ryan and Sophie go to Mako Island to obtain rare crystals, but they end up damaging the moon pool, causing its magic to be gone. Ryan only appears in Season 3. Ryan also continuously asks for Cleo and him to meet up some time out side of work but it never really happens .