The Indonesian Cakra class submarine KRI Nanggala 402 (C) setting out from the naval base in Surabaya in an undated file photo. - Indonesia's military said it was searching for the submarine with 53 crew aboard after losing contact with the vessel during naval exercises off the coast of Bali on April 21, 2021. Photo: AFP / Handout / Indonesia Military

JAKARTA – Answering the call of the distressed mariner, as they have done through the ages, ships and aircraft from five countries joined the desperate search for the Indonesian submarine KRI Nanggala-420, now declared lost with all 53 hands in deep waters off the tourist island of Bali.

Singapore, Malaysia and India mobilized submarine rescue vessels, Australia dispatched an Anzac-class frigate and fleet tanker, and the United States sent a sophisticated P8 Poseidon maritime patrol aircraft and search and rescue equipment from Japan and the US East Coast.

France, Germany, Russia, Turkey and South Korea — the builder of three of Indonesia’s five submarines — also offered their assistance as part of the International Submarine Escape and Rescue Liaison Office’s (ISMERLO) emergency response scheme.

But with only a three-day supply of oxygen and an additional 18 crewmen apparently added to the usual 34-man complement, it was always going to be a losing race against time to find anyone alive aboard the German-built Type-209 submarine.

What began as a rescue has now turned into a recovery operation centered on an area 45 kilometers north of the Bali coast where a remote-operated vehicle from the Singapore rescue vessel MV Swift Rescue found wreckage at a depth of 838 meters – well beyond the submarine’s designed limit of 500 meters.

Navy chief Admiral Yudo Margono said the diesel electric-powered Nanggala had broken into three parts, with video beamed back from the deep-diving submersible showing the vertical fin still attached to the aft section of the boat and an anchor resting on the seafloor.

It won’t be until an international salvage team recovers the wreckage and the bodies of the crew that investigators will be able to determine what went wrong, but Margono said he was convinced human error was not involved.

This handout photo shows parts of the missing submarine which has been found cracked apart on the seafloor in waters off Bali island, APril 25, 2021. Photo: Handout / Indonesia Military / AFP

“If it was an explosion it would be in pieces, (but) the cracks appeared gradually in some parts when it went down, from 300 meters to 400 meters to 500 meters,” he said. “If it were an explosion, it would have been heard on sonar.”

One former Australian submariner says an explosion should also have been picked up by seismographs used to monitor Bali’s Mt Agung, the island’s largest and most active volcano.

A day earlier, navy searchers found several pieces of debris, including two prayer mats and an orange escape suit, indicating the boat had broken up and leading Margono to declare: “We have now moved from a ‘Submiss’ phase to a ‘Subsunk.’”

The German-built submarine disappeared shortly after receiving clearance to dive at the start of a live-firing exercise that was to have been observed by armed forces commander Air Chief Marshal Hadi Tjahjanto from a surface vessel. 

The only similar previous disaster in Asia was in April 2003, when a critical air intake valve failed dooming the 70-man crew of the Chinese submarine Changcheng-361 during an exercise in the Yellow Sea. It too was carrying more than its normal complement.

China did not call for international assistance and only acknowledged the fate of the Ming-class submarine six days after a fishing boat noticed the periscope of the drifting craft. The crew was subsequently found slumped dead at their stations.

Before the latest tragedy, five Russian and two American boats, most of them nuclear-powered, were among the 10 submarines involved in major disasters over the past six decades. Together, they claimed 796 lives.

Since 2000, collisions (12), fires and explosions (7), groundings (3) gas leaks and other mechanical failures have been responsible for most of the 30 less serious submarine incidents.

The loss of the Nanggala, the oldest in Indonesia’s small submarine fleet, shows that when disaster strikes underwater, a submariner’s life is often measured in hours, if not minutes.

Indonesian military chief Hadi Tjahjanto reacts during of sunken Indonesian Navy submarine KRI Nanggala 402 at Ngurah Rai Military Air Base in Kuta, Bali, Indonesia on April 25 2021. Photo: Johanes Christo/NurPhoto via AFP

Although the crew would already have been dead at that point, the Swift Rescue was still 11 hours away from the scene when the oxygen deadline passed in the early hours of April 24. Malaysia’s MV Mega Bakti had 28 hours to go and India’s SCI Sabaramati was still days away.

The Poseidon landed in Bali just before the deadline after a 14-hour flight from Japan’s Kadena naval air station, lengthened by a diversion to Guam for a refueling and rest stop after a super typhoon closed Philippine airspace.

The deployment of the P8 comes a year after Indonesia rejected a US request for the long-range aircraft to use Indonesian airbases for refueling on missions tracking Chinese warships and submarines across East Asian waters and the Indian Ocean.

Sticking to a long-held policy of neutrality, Indonesia has never granted basing or replenishment rights to foreign powers, but it is wary of recent Chinese encroachments and does engage in regular exercises with US and Australian forces.

Indonesia has had longer experience with submarines than most Asian countries. Through the Cold War in the 1960s, it operated 12 Soviet Whiskey-class boats acquired from the Soviet Union, more of the underwater craft than any navy in the southern hemisphere.

Advances in construction methods, safety practices and other high technology developments along with improved training processes and operational doctrine have made submarine operations a lot less hazardous than they were.

But the latest tragedy is likely to compel a re-examination of ways for submarine operators to improve multinational disaster coordination beyond triennial Pacific Reach exercises and an annual Asia-Pacific Submarine Conference. 

Currently, there are 15 submarines operating in regional naval inventories, including Vietnam (6), Indonesia (5), Singapore (3), Malaysia (2) and Myanmar, which surprisingly took delivery of a former Indian Navy Kilo-class submarine last year. 

This undated handout from the Indonesia Military released on April 21, 2021 shows the Indonesian Cakra class submarine KRI Nanggala 402 docking at the naval base in Surabaya. Photo: Handout / Indonesia Military / AFP

Indonesia’s three Korean-built Type-209s, Malaysia’s French Scorpion-class craft, Singapore’s Swedish-supplied underwater fleet and Vietnam’s super-silent Russian Improved Kilo-class submarines were all commissioned in the past 16 years.

Singapore currently has four Invincible-class submarines under construction in Germany and Indonesia has three more Type 209s on order but Thailand last year shelved a controversial US$1.1 billion plan to buy three Chinese S26T submarines.

“With the creation of new submarine fleets as well as the expansion of current operators in Asia, the risk of peacetime submarine accidents is likely to grow,” military expert Kelvin Wong wrote in a prescient 2009 paper for the S Rajaratnam School of International Studies (RSIS).

“The relatively confined waters of Asia, with its busy shipping routes and difficult underwater terrain, also heighten the probability of a mishap. Submarine services in Asia are likely to be needed more than ever as regional navies attempt to exploit the depths.”