Ghalib Kabir on July 24, 2023, made some interesting comments on the increasing difficulty of submarines operating in the generally shallow South China Sea (SCS).
It is suspected that China is laying undersea sensors of increasing quality and quantity. These are criss-crosing the SCS from and between the Chinese mainland and around Taiwan, China's Hainan Island province and between China's new SCS militarised islands (in the Paracel and Spratley island groups). Also China has increasing number of mobile sensors and weapons platforms, including increasing numbers of SSNs and Yuan SSKs to weaponise the sensor networks.
This sensor saturation of the SCS means Australia's current Collins will need to avoid their regular SCS mission area. Also even Australia's Virginias (if the RAN ever receives them) may not be able to specialise in SCS missions.
Ghalib Kabir comments:
The 209s, Scorpenes, any future 218s, 212 derivatives etc will face a simple fact in the SCS.
The SCS is a shallow sea and the Chinese have bugged the damned sea floor with sensors already.
Here is a helpful extract from good ol' USN on the SCS,
"Nearly half its seabed is continental shelf in water depths less than [650 feet/200m] a single deep basin with several depths to more than [5,000m] makes up only 16 percent of the South China Sea."
See The South China Sea: Complex and Changing by Captain Lawson W. Brigham, U.S. Coast Guard (Retired), Published at U.S. NAVAL INSITUTE January 2023 Proceedings Vol. 149/1/1,439
[Down to 200m depths only] very quiet subs could have a chance. 200m in 70-80% of the SCS makes it prime territory for using expendable UUVs and [surfaced] USVs. The PLAN will face the same problem Autralian or other nations subs will face...shallow seas...ocean floor sensors can "ping" [active sonar pulses and perhaps LED or laser pulses] and get the readings of even Li-AIP subs crawling at 2 knots at 150m.
If war breaks out no Taigei/Soryu/U212 is going to survive for long against the giant dragnet the PLAN will activate no holds barred. On the other hand, the Yuans...even the so called 'ultra quiet' Type 039Ds might not be invincible....
Lastly.... I think any RAN Virginia would have to be an SSGN that can fire hypersonic missiles if need be....[at Chinese ships and islands in the SCS]
We have discussed this since 2015...if the fat falls into the fire...then the Quad will need a mix of USVs, UUVs, XLUUVs, Manned special mission midget subs, AIP-Li SSKs and SSGNs along with surface fleet and Naval Air arm with P-8 MPAs, E-2D AEWs, MH-60R ASW, "Growler" EA-18Gs, F-35s and Sea Guardian [Reaper variant] MQ-9s capable of EW, LRSTOW [missiles with lightweight torpedoes?] launch....plus the ability to knock out Chinese Yaogan reconnaissance satellites and other Chinese military satellites to blind the PLAN and PLAAF.
We either go all in or risk a solid pasting in the first island and second island chains.
This Tom Clancyesque fleet scenario is no more a joke...China can deploy 50 Type-54 frigates with 40 VLS each, 30 plus Type 052Ds with 80 VLS each and 15-20 Type 055 cruisers with 128-144 VLS each...plus 70 Chinese SSNs and SSKs with a combined missile capability 400-500 VLS equivalent....
As China's population ages and economically feels the pinch...trust them to find an outlet by picking a quarrel just as they did with India in 1959-60 in the middle of the great leap forward disaster..."