When HMAS Hammersley answers a distress call from Bright Island, Captain Mike Flynn and his crew discover a young woman lying paralysed on the beach. She is conscious but unable to talk, and despite their best efforts they are unable to save her. Thus begins new Executive Officer Lieutenant Kate McGregor's first day aboard a patrol boat, and CO Mike Flynn's obsession with the mystery of Bright Island. Something very odd is happening in connection with the Island. The Federal Police move in to investigate the woman's death, but no-one is talking. Her colleague, the striking Doctor Ursula Morrell, seems to know more than she's letting on, and Mike finds himself drawn to her cool beauty and her vulnerability.

The Hammersley uncovers a sophisticated drug smuggling network, with explosive results. Mike is convinced the Federal Police are covering up the poisoning death of a marine biologist. Kate is jealous of Mike's relationship with Ursula Morrell, while Nikki struggles to restrain her feelings for ET.

The crew of the HMAS Hammersley come across an abondonned catamaran in the middle of the ocean, which uncovers the beginnings of a murder mystery. A sailor has gone missing and Nikki puts her navigational sklls to the test in the attempt to find them. The ship is then hit by a cyclone.

The Hammersley attempts the daring capture of an illegal fishing ‘mother ship’ but is thwarted by violent eco-terrorists. Mike finds himself falling in love with beautiful marine biologist Ursula Morrell, who later goes missing under mysterious circumstances.