 This service included conducting risky surveillance missions against India and Communist nations in South East Asia.These missions were cancelled in 1992 when an Australian submarine, believed to be "Otama", became tangled in fishing nets and was forced to surface in the South China Sea.The "Oberon" class regularly conducted exercises with the Special Air Service Regiment (SAS) and to a lesser extent the 1st Commando Regiment and the Clearance Diving Branch.