Mike 'CO' Flynn (Ian Stenlake)
- Authority Equals Asskicking: Deserves his reputation and shows it when he is given a chance.
- Green-Eyed Monster: Over Kate. Despite being the one who ended the relationship whenever Kate gets close to another man he gets jealous. It becomes obvious even to him with Kate's first relationship with Jim and comes to ahead with 2Dads' rumour about Buffer and Kate.
- Uptight Loves Wild: Has reputation as a cowboy and falls for by-the-book Kate.
Kate 'XO' McGregor (Lisa McCune)
- Damsel out of Distress: Whenever she's in troble all the bad guy tead to forget that she's in the navy and leads a team of manly men who respect her. The amount of times she's in danger that she can't handle can be counted on one hand.
- Good with Numbers: Is an qualified navigator.
- Love Martyr: Is left by Mike before the series begins without an explaintion when she seems to have fallen half in love with him and is still bitter about it when she is posted to Hammersley. Mike ignores her obvious feelings of abandonement and openly goes after Dr Morrell and refuses to hear anything against her from Kate until he can't ignore any longer. Then he starts showing interest in her when she finds a good man to date and shows her up infront of the crew after she is slightly late after a meeting with Jim. He then makes it clear that he would date her again if he could leaving her speechless. When he is nearly killed she admits to him while he is unconusure that she loves him which Jim overhear and they end their relationship. He didn't hear but their relationship goes smoothy for a time until 2Dads rumour about her and Buffer being in a secret relationship gets to Mike and Kate is clearly embrassed infront of him. Then Mike finially gets an promotion and leaves Hammersley and it looks good for then then Mike sides against 2Dads in an incident with a baby crocodile leaving Kate feeling betrayed on 2Dads behalf. Mike comes round to her house and they have an arguement and she lets him have a piece of her mind. He kisses her and they have sex. Then he is reasigned to Hammersley and they put they relationship on hold for the rest of the season party because Mike is relucate to leave Hammersley. His relationship with Maxine White also makes her jealous. She then suffers a huge Heroic BSOD when he seems to have been blown up in the series 4 final and has to hold it together for the crew. Mike is found to be alive but he ends up staying on Hammersley and when she applies for a promotion it is hinted that she is turned down because of their relationship. Maxine White then convines her to end the relationship for Mike's benifit and she date Jim again but by this time Mike has fallen for her completely and is aware of the damage he is doing to her and tries to make up for it.
- Uptight Loves Wild: Is a by-the-book ice queen who falls for cowboy Mike.
Nicole (Nikki) "Nav" Caetano (Saskia Burmeister)
- Action Girl: A mild example since she is rarely in any fights but when she is she holds her own.
- Good with Numbers: Is the ship's navigator.
- Tsundere: She loves ET, but because they can't act on the relationship, ET's antics drives her nuts.
Pete 'Buffer' Tomaszewski (Jeremy Lindsay Taylor)
- Papa Wolf: To the crew. Mike has to make it clear occasionally (when they've got the person who's involved with the injury) that they can't get bruises from falling down the stairs.
- Subordinate Excuse: Sort of. The majority of women he shows interest are all officers.
Andy 'Charge' Thorpe (John Batchelor)
- Beware the Nice Ones: Is one of the nicest members of the crew but when he gets angry or someone he likes is in danger or hurt, watch out...
Chris 'Swaine' Blake (Matthew Holmes)
- The Driver: The main person behind the ship's wheel.
Robert 'RO' Dixon (Kristian Schmid)
- Ambiguous Disorder: He has a very black and white view of the world, and when asked if this was true he responded "I'm not racist." Then there's his believing Bomber fancied him after she gave him a peck on the cheek, and him not wanting to take credit for saving her life because she told him not to go near her.
- Badass Bookworm: Might be the least phsyical man on the boat but don't cross him.
- Camp Cook: When Bomber is away. Anything she has done wrong is instantly forgiven.
- Cunning Linguist: Has picked up bits and pieces after years of working on patrol boats.
- Jerk with a Heart of Gold: Isn't willing to go out of his way to help people when he easily can, is blunt to the point of rudeness and doesn't socialise easily. However he repeatly shows that he has a heart and after a while his lack of social interaction with the rest of the crew worries him enough that he begins to inprove.
- Loners Are Freaks: Has a problem with this perception though he doesn't do much to discourage it.
Josh 'ET' Hoilday (David Lyons)
- AB Negative: Saves Charge's life at one point.
Toby 'Chefo' Jones (Josh Lawson)
Billy 'Spider' Webb (Jay Ryan)
- Too Dumb to Live: Yeah Spider, go and change the biggest badass' tattoo choice to XO in a heart when he's asleep. You're lucky Buffer just put your head into the washing machine.
Rebecca 'Bomber' Brown (Kirsty Lee Allan)
- Put on a Bus: Because of her romance with 2Dads, she's discharged from Hammersley.
- The Squadette: Among the NCO during the second and third seasons.
Leo '2Dads' Kosov-Meyer (Nikolai Nikolaeff)
- Establishing Character Moment: Is able to tell that a stall owner is selling stolen property just by looking at it and then uses dud money to buy their monkey to smuggle it back to Austrailia without going though customs on the Hammersley.
- Everything'sBetterwithMonkeys: Learns the hard way that this isn't always the case.
- The Gambling Addict: Always finds a poker game but cheats occasionally which is when his problems start.
- Hero-Worshipper: 2Dads has some of this to Dutchy in series 4.
- Malicious Slander: Spreads a rumour about Kate and Buffer after an deservedly harsh dressing down.