The crew of Hammersley is rocked by the mysterious death of a much-loved shipmate. When valuable "Red Gold" coral is stolen from a dive boat, HMAS Hammersley is drawn into a web of murder, piracy and eco-terrorism. Then, Swain and Spider are kidnapped by an obsessed vigilante, determined to rid Australian waters of illegal fishing boats.

A new crewmate and a stowaway cause mayhem on board HMAS Hammersley. Nikki and Charge are taken hostage by foreign pirates, with explosive results. Nikki is close to breaking point, following the death of her fiance.

Mike and Spider are taken hostage during a shoot-out with weapons smugglers. Kate fears her past relationship with Mike will become public knowledge. The Hammersley rescues a former Navy officer lost at sea, with shocking consequences for the crew

Nikki starts investigating the mystery behind ET's death. But can she handle the truth? Swain risks his life to save a boy suffering from the bends. Spider tries to free a child slave from an illegal fishing boat, but lands himself in hot water. Tempers fray when Hammersley rescues an old enemy following a bizarre diving accident.

Hammersley is tasked with protecting a shipment of nuclear waste from a terrorist attack. When a bomb is discovered on board, Robert and 2 Dads must set aside their differences to save Hammersley. Buffer falls victim to a practical joke and Robert is tricked into going on a drunken date, with disastrous results.

The crew is exposed to toxic radiation during a daring rescue at an abandoned nuclear test site. Swain's courage is called into question, when he opts out of a high-risk rescue operation and Charge uncovers a military conspiracy over nuclear testing and a long lost B-25 bomber.

Kate is terrorised by a mysterious stalker on board an abandoned cargo ship. Spider contracts deadly coral poisoning during a bizarre snorkelling accident and Buffer and 2Dads face a freezing fate in a tropical paradise.

Hammersley hunts down a mysterious gang of armed robbers, who are terrorising pearl luggers off the WA coast. Spider and Buffer have a trippy encounter with some hard-partying drug smugglers. 2Dads faces disciplinary action for negligence. Also, Mike is forced to intervene over rumours that Kate and Buffer are romantically involved.

Buffer gets a lesson in tough love from a sexy training officer. Hammersley is stranded in a deadly mine-field, after being attacked by heavy armed smugglers. Charge goes to extreme lengths to earn the respect of his estranged son and the crew are involved in a sailor's worst nightmare - fire at sea.

A thrilling rescue becomes a tragic mystery when a healthy young tourist dies suddenly on board Hammersley. Bomber and RO fight for their lives when an armed gang tries to seize control of Hammersley. Nicki receives a death threat while investigating ET's diving accident.

A rescue at sea casts doubt on the circumstances of ET's death. While searching for a missing kayaker, Buffer stumbles across an illegal oil smuggling operation. Charge's weight threatens to sink his navy career. Will he become the biggest loser?

In an explosive series climax, Mike and his crew takes extreme action to thwart an oil smuggling conspiracy and avenge ET's murder. Nikki risks everything to uncover the truth about ET's final moments. Kate is trapped in a deadly showdown with one of ET's killers.