The Branch has evolved from traditional maritime diving, and explosive ordnance disposal, to include a special operations focus.

[13] In late 1966, Clearance Diving Team 3 (CDT 3) was established specifically for deployment to the Vietnam War to assist the overworked United States Navy Explosive Ordnance Disposal units, and to give RAN personnel in clearance diving work in an operational environment.

Maritime counter terrorism-explosive ordnance disposal (MCT-EOD):[20] A Clearance Diver may be posted to a Clearance Diving Team, Huon Class Minehunter Coastal ship, training position in the Australian Defence Force Diving School at HMAS Penguin and can apply to serve in the Tactical Assault Group-East (TAG-E).

[30] Since January 2002, Special Duties Units of Clearance Divers from AUSCDT1 and AUSCDT4 have provided the maritime counter terrorism element of Tactical Assault Group-East (TAG-E), attached to the Australian Army 2nd Commando Regiment, which became operational on 22 July 2002 to respond to terrorist incidents in the Eastern States of Australia.

CDAA is aimed to ensure officer and sailor clearance diver candidates have the right aptitude to commence the lengthy training program.

During CDAT, candidates began each day at 02:00, and were put through over thirty staged dives designed to test their strength and endurance.

[36][38] The MCT-EOD role requires clearance divers to be trained in specialist insertion techniques including diving, fast roping and parachuting.