November 27, 2015

Japan's Submarine Deployment Areas, Straits and Ports

Japan's major straits (with possible patrol details below)

[According to this open source] During the Cold War the Japanese Navy's active 16 submarines mainly watched three straits for Russian subs. At any one time around 3 submarine may have been available to watch each of the following straits:

-  the Soya Strait [aka La Perouse Strait) (between Hokkaido and Russia's Sakhalin island), 
-  the Tsugaru Strait (between Honshu and Hokkaido), and 
-  the Tsushima Strait between Kyushu and South Korea. 

Since the end of the Cold War and with the rise of Chinese naval power, some of Japan's subs have been diverted to patrol waters in the East China Sea around the Nansei (aka Ryukyu) Islands (island chain between Kyushu and Taiwan). Japan now has 18 active (Oyashio and Soryu class) submarines, with plans to raise the number to 22 by 2018.

US Air and Naval Bases in Japan, (not too many Japanese Base maps available!) But note:

-  the Japanese Navy's s fleet and sub HQ is at Yokosuka (including Submarine Flotilla 2 with about 9     Oyashio and Soryu submarines)  and
-  at Kure (near US Marines Iwakuni Base) is Submarine Flotilla 1 about 9 Oyashio and Soryu subs)

In a remarkably detailed open source description - the following are excerpts of a Sentaku Magazine's article via The Japan Times, November 26, 2015

"Japan’s crack submarine fleet

The central headquarters of both the U.S. Navy [Seventh Fleet] in Japan and the [Japanese Navy] are located in Yokosuka, Kanagawa Prefecture, and [the Japanese Navy's] submarines’ operations are effectively integrated with the U.S. Navy.

During the Cold War, the U.S. Navy entirely entrusted to [the Japanese Navy's] submarines the role of watching the movements of Soviet submarines in the Soya Strait between Hokkaido and Sakhalin, the Tsugaru Strait between Honshu and Hokkaido, and the Tsushima Strait between Kyushu and South Korea.

The American reliance on those [Japanese Navy] submarines stemmed from their excellence in small-turn performance [maneuverability]. They are capable of navigating over topographically complicated sea floors with steep uphills, gorges and tangled sea currents in pitch-dark conditions, usually moving at a speed of 5 knots. Today, [the Japanese Navy's] submarines can trace every movement of Chinese naval vessels, including subs, from their port departure to every point of their routes, by utilizing an analysis of information sent from U.S. reconnaissance satellites as well as radio waves.

Before the collapse of the Soviet Union, the [Japanese Navy] had 16 submarines and deployed three each in the Soya, Tsugaru and Tsushima Straits with the remaining seven under repair or engaged in training exercises. Lately though, with the rise of Chinese naval power, many of [the Japanese Navy's] submarines are being shifted to waters around the Nansei (aka Ryukyu) Islands (the island chain between Kyushu and Taiwan). The [Japanese Navy], which now has 18 submarines, plans to raise the number to 22 by 2018.

Critical areas of [the Japanese Navy's] submarine activities aimed at China are the Tsushima Strait, the Miyako Strait between Okinawa Island and Miyako Island, and the Osumi Strait off the southern tip of Kyushu, each of which constitutes a passageway through which Chinese naval vessels must pass to move from the East China Sea to the Pacific Ocean.

…Moreover, [the Japanese Navy's] submarine crew members possess outstanding skills for detecting the position and movement of enemy vessels by analyzing and processing the sounds emanating from them. The subs’ sonar equipment, including a towed array sonar trailing behind a submarine for several hundred meters, has the capability to detect sounds coming from a vessel up to 80 km away.

…Some time ago, Adm. Wu Shengli, commander of the Chinese People’s Liberation Army Navy, told a high-ranking [Japanese] Self-Defense Forces officer that his navy was aiming to become a “blue-water navy,” meaning that it would become capable of operating across the deep waters of open oceans. In the 1990s, China was known to have only a “brown-water navy,” which can operate only in rivers and coastal areas. True to Wu’s words, China has since been endeavoring to expand its areas of operation into the Pacific.

The East China Sea, where [the Japanese Navy's] submarines are deployed, has long stretches of continental shelves, making the average depth only 180 meters, and some areas only 50 meters. That is why China now looks to the South China Sea, where waters are 3,000 to 4,000 meters deep in a number of areas, and has concentrated its state-of-the-art submarines in the South Sea Fleet [with many subs of that fleet based at Sanya/Yulin, in China's Hainan Island].

That has led the Japanese Defense Ministry to keep an eye on the 150-km-wide Bashi Channel [Luzon Strait] between Taiwan and the Philippines, which could be used by Chinese submarines as a gateway to the Pacific, which in turn could rapidly increase confrontation with [the Japanese Navy's] submarines around the [Bonin Islands] and other Japanese islands in the Pacific.

The capabilities of [the Japanese Navy's] submarines today far surpass those of their Chinese counterparts [eg. Yuan class subs]. But [a Japanese naval] officer has warned that if China secretly obtains advanced technologies from various countries and combines them like a jigsaw puzzle, the day may come when Chinese submarines will be on a par with those of [the Japanese Navy]…” See WHOLE ARTICLE

Please connect with Submarine Matters Possible Japanese Submarine Deployment Area, February 20, 2015 which also describes the rising importance of the Bashi Channel (Luzon Strait) as a deployment area.



Nicky said...

HI Pete,
It's what boomers call Boomer banks where SSBN's go and SSN's guard them like a shark.

Nicky said...

Hi pete,
Check out this link and movie

North Story - The Orkanfahrt of U 31,sendung447848.html

Peter Coates said...

The opost turned out to be so long that it may get auto-deleted - so I'll do the post in 2 segments.

Hi Nicky

Thanks for your comments.

Re [November 28, 2015 at 1:16 PM] The word "Orkanfahrt" has me intrigued. Fahrt means trip while Orkan might be under water like an Orca. So my non-German speaker guess is "Orkanfahrt" is underwater voyage.

(Interesting the Captain wearing the old style battered U-Boat cap :) The U-31's electronics look ultra-modern especially compared to Yuans and Kilos.

The intro translation for video is,sendung447848.html is:

"U-boat commander Lars Gössing * and his 28-strong crew Delta have a mandate to participate with their submarine U 31 at a naval exercise in the Royal Navy. 1,000 nautical miles, or nearly 2,000 kilometers above water drive from Eckernförde to Plymouth in southern England are the captain and his crew.

U 31 [is a class 212A] and is the most modern non-nuclear submarines type worldwide. With 56 meters long, seven meters wide and almost twelve meters, the submarine has 180 square meters of space for people, technology, two tons of food and equipment.

Poor weather forecast for the North Sea

During the transit journey, and their use of the captain and crew their families and friends will be separated. You are in a confined space without natural light, highly concentrated in the six-hour change of guard work together. A life without privacy, except their own bunk, which is manageable with two meters in length and 60 centimeters wide.

The weather forecast for the North Sea looks bad, it is announced up to wind force nine. A challenge for captain Gössing, whose job it is to bring boat and crew back home safely. The first days at sea are determined by board routine. In the rhythm of the six-hour guard shift work, eat and sleep the men.

Peter Coates said...


Exercises include onboard security on transit journeys also to how the daily clean ship making. As long as the sea is calm, make some crewmembers even sports. In propeller engine compartment at the rear of the boat are their fitness equipment.

The situation comes to a head

After five days at sea, the weather changes. U 31 fights by the ferocity of the North Sea, with sailors known as one of the most dangerous sea areas. The situation comes to a head when the crew gets a hurricane warning for the marine environment and to which they set sail.

On the seventh day at sea, the predicted hurricane U 31 meets before the entrance to the English Channel. Twelve winds from the southwest and up to twelve meters high waves. The situation is critical, because now damage can be seen on boat through the periscope. For six hours the hurricane rages and shakes the boat and its crew through. Only the next day, it is the team's possible to go to the bridge and to assess the damage.

* Editor's note: Lars Gössing was at the time of filming commander of U31. He has since taken on other tasks in the Navy."

[a shorter 10 minute Youtube of U-31's voyage to Plymouth,UK is at ]



Nicky said...

Hi Pete,
Check this out from India and you can see what the Indian Navy Kilo class Submarine looks like from the inside.

In underwater battle, India 'annihilates' American n-submarine
If the hostile entry of United States Navy 7th fleet in the crucial stage of the 1971 war for the liberation of Bangladesh sent a shiver down the spine of Indian military commanders, events of last month gave them some relief.

Nicky said...

HI Pete,
I wonder what the Type 212 would look like in Australian waters and would it handle it

Peter Coates said...

Hi Nicky [at November 29, 2015 at 5:22AM]

At . In those Malabar near India waters the home team (Indian sub) may well have greater knowledge of the littoral undersea landscape. Hence an advantage.


Peter Coates said...

Hi Nicky

An excellent Indian submarine Youtube. about Indian Kilo INS Sindhukriti.

3min 25secs in shows many advanced looking combat system and steering screens

7m 40s in battery checking twice a day. Looks labour intensive - perhaps remote sensor system checking batteries more effecient.

8mins - amazingly cramped and hot engine room. Pays not to be 6 feet tall!

9m 50s India ELF antennass at aid in submarine navigation/positioning and to send commands to subs in the Indian Ocean

12m crew is 53, but "average of 70 serve on board". Presumably for short missions?

15.30 selection, recruitment, training,

20.20 need for reform and updating in India's submarine program, news subs needed, Chinese subs much more modern.

May turn this into an article if there's time.


Peter Coates said...

Hi Nicky [Nov 29, 5:26AM]

As Australia is using the electrical power hungry US combat system the engines/size of 212s, 214 and Scorpene are inadequate. Possibly even 218s are too small.

So 216, Shortfin or Super Soryu may be sized to feed the US combat system.



Nicky said...

Hi Pete,
Not a problem. I think India needs to revamp it's submarine program to meet 21st century. That's why I think for the Indian Navy their's a division between the old timers who like the soviet gear and younger gen who likes the more western gear.

MHalblaub said...

Dear Nicky,
The video must be rather old. I have seen it years ago.

The problem within the English Channel is the water deepth. A German submarine can operate submerged there but there is not enough space for a submarine and a ship. There is a hell of traffic in the Channel.