Main Characters Lieutenant Nikki "Nav" Caetano 26 main appearances Petty Officer Chris "Swain" Blake 26 main appearances Leading Seaman Josh "ET" Holliday 26 main appearances Lieutenant Kate "XO" McGregor 26 main appearances Seaman Billy "Spider" Webb 26 main appearances Leading Seaman Communicator Robert "RO" Dixon 26 main appearances Lieutenant Commander Mike "CO" Flynn 26 main appearances Petty Officer Bosun Peter "Buffer" Tomashevski 26 main appearances Chief Petty Officer Andy "Charge" Thorpe 26 main appearances Able Seaman Rebecca "Bomber" Brown 13 main appearances Able Seaman Cook Toby "Chefo" Jones 13 main appearances Petty Officer Bosun Dylan "Dutchy" Mulholland Midshipman Ryan "Ry" White Seaman Jessica "Gap Girl" Bird Leading Seaman Leo "2 Dads" Kosov-Meyer
Recurring Guest Characters Commander Steve Marshall 15 guest appearances Lieutenant Darryl Smith 12 guest appearances Federal Agent Greg Murphy 9 guest appearances Dr. Ursula Morrell 6 guest appearances Ray Walsman 6 guest appearances Federal Agent Alicia Turnball 5 guest appearances Carl Davies 4 guest appearances Seaman John Jaffah 4 guest appearances CMDR Steve Marshall 4 guest appearances Rick Gallagher 4 guest appearances HMAS Hammersley Sailor 4 guest appearances Sally Blake 4 guest appearances Carly Walsman 4 guest appearances Dr. Lee 3 guest appearances Franz Szapolyai 3 guest appearances SAS Captain Jim Roth 3 guest appearances Sam Murray 2 guest appearances Dr. Poulos 2 guest appearances Suzie 2 guest appearances Able Seaman Harry Costa 2 guest appearances ⇤ « 1 2 3 4 5 6 7 8 » ⇥