Royal Australian Navy submarine HMAS Rankin is seen during AUSINDEX 21, a biennial maritime exercise between the Royal Australian Navy and the Indian Navy on September 5, 2021

India and Australia on Thursday participated in the fourth iteration of the biennial maritime series 'AUSINDEX'

Chief of Navy Australia Michael Noonan, in a tweet, called the maritime exercise a vital opportunity to showcase Australia's ability to conduct high-end maritime warfare training with India and showcase a range of 'AusNavy' maritime capabilities.

The fourth iteration of the biennial maritime series #AUSINDEX took place with @indiannavy. It was a vital opportunity to showcase #OurPeople's ability to conduct high-end maritime warfare training with our Flag of India counterparts & showcase a range of #AusNavy maritime capabilities," Chief of Navy Australia said in a tweet.

Commenced in 2015 as a bilateral maritime exercise, AUSINDEX has grown in complexity over the years and the 3rd edition of the exercise, held in 2019 in the Bay of Bengal, included anti-submarine drills for the first time.

In the fourth edition, the surface units of both the countries will be exercising with HMAS Rankin, a Collins Class Australian Submarine, Royal Australian Air Force P-8A and F-18A aircraft, along with integral helicopters of both the navies.

The release said that the exercise will provide an opportunity for both navies to further bolster inter-operability, gain from best practices and develop a common understanding of procedures for maritime security operations.