Senior Sergeant Dave McCall was the blunt, sarcastic head of the divers. He was one of the best in his field but was no longer able to dive after being on the receiving end of a spear from a booby-trapped car; however he continued to be in charge of the dive unit. Dave left the Rats without any explanation and much later we found out his marriage had broken up, he was on stress leave and he had been found dead on the toilet.

Senior Constable Terrence Watson was a tall, tough, stubborn diver. He had worked hard to get where he was and often seemed to resent those with more privileged backgrounds. He was a good diver and a good copper. He developed a great relationship with Fi, but in the end she decided her career was more important. Terry jeopardised his career when he slept with a woman he had rescued. Terry ended up leaving the Rats, but he reappeared later on when his daughter was kidnapped.

Constable Emma Woods was the popular female diver. She was fun, fiesty, a great team member, she loved what she did and was very good at it. Woodise was very loyal to her colleagues, but always gave the macho men on the diving team something to keep up with. It was only towards the end of the series that Woodsie gained a more prominent role and even then Woodsie-fans didn't think it was enough.

Senior Sergeant Lance Rourke took over from Dave being in charge of the divers. He was also quite sarcastic and didn't waste words. Yet another talented diver, he had slightly more compassion for his colleagues than his predecessor, but he didn't take crap from anyone. In a tragic operation gone wrong, Lance was crushed by a shipping container, leaving the Rats devastated by another death.