The HMAS Hammersley confronts a series of new menaces in the northern waters from pirates to toxic crabs, not to mention a gorgeous solo yachtswomen with a rescue fetish.

Disaster looms for the Hammersley crew when a fire erupts in the engine room, after the mascot is stolen by a rival Patrol Boat crew. Meanwhile, an eye injury threatens to destroy Charge's career, and ET takes a vow of chastity in a desperate attempt to prove himself to Nikki.