"Nani?! A solo submarine?! Nakasa Kijima was also taken aback, because in his concept, such a thing could not have happened.

He was a graduate of the 44th class of the Naval Academy, and after graduation he served in the submarine force for 12 years as a submarine captain, accumulating enough seniority before he was promoted to commander of the war.

Guidao has served as a captain on five submarines, one of which is on the Yi 60 at his feet, although most of the crew of the year have retired at this time, but Guidao can be said to know the performance of this ocean-going submarine well.

The special construction of the submarine makes it impossible for it to search for surface targets as easily as other surface ships. It is known that the height of the submarine conning tower is low, which, although it gives her good concealment, at the same time reduces the distance of lookout observation, since the surface of the earth is curvature.

Therefore, submarines must rely on other technical detection means to find targets above and below the sea surface, and the most commonly used equipment is underwater hydrophones, which can be regarded as passive sonar in later generations. The listener does not actively emit sound waves, but passively receives the sound in the seawater, and the highly trained operator can distinguish the sound of the ship's propeller and engine from a piece of seawater noise, and the skilled operator can even calculate the speed and general course of the other party by means of the angle change between the sound source and the boat.

However, it is really unbelievable that the submarine of the Independent State actually surfaced at such a close distance from the Yi-60, and the listening device on the Yi-60 did not notice the slightest abnormality in advance.

"If it's not the receiver that's malfunctioning, it's the operator's negligence, and this has to be investigated." Holding on to the large telescope mounted on the open platform behind the bridge, Kijima turned his lens to the German submarine in front of him.

The 12-centimeter binocular telescope produced by Japan Optical Industry Co., Ltd. (then part of the Mitsubishi Foundation, later Nikon Company) is the standard equipment of Japanese naval ships, and the submarine is equipped with a specially customized waterproof model, in fact, a metal waterproof cover with a rubber washer is installed at the eyepiece position, which is usually turned up above the lens barrel, put down before diving, and sealed with large bolts. This is the originality of Japanese submarines, so that when unsuspecting outsiders see the huge waterproof cover that has been turned up, they often mistake it for some kind of Japanese high-tech equipment.

Under the magnification of 20 times, the unique command tower of the German U-boat is as close as if it is close at this moment, and you can clearly see several German naval officers and sailors on your island, who are also observing themselves with binoculars.

"Commander, maybe it's been muffled by other noises..."Hanafang also wanted to explain to his subordinates, but in exchange for a stern reprimand from his boss.

"Red deer! Greenhouse! You're an old captain, too! Don't you blush when you say something like that! "Guidao let go of the large goggles and handed them back to the lookout who was originally operating.

"The submarine is turning, approaching at a slow speed." The lookout standing at the top of the bridge reported in time, and only then did he turn the attention of the two officers to the German ship in front.

At this time, the access hatches of the front and rear decks of the U106 were all opened, and the German sailors wearing khaki tropical uniforms were climbing onto the deck one after another.

"All recorded, this is the main ocean-going submarine equipped by the Japanese Navy." Captain Robin put down his binoculars and turned his face to the second officer, who was holding an eight-millimeter film camera in his hand.

"Don't worry, Captain." The duty officer replied with a smile.

"It's a big boat." Lieutenant Igor lit a cigarette and passed the lighter to the captain.

"Judging from the data provided by the headquarters, she is more than 800 tons more than us, but after seeing the real ship, I feel that the difference is far more than that, you look at the size of this thing." Robin was hooked by the co-captain, and he pulled out his cigarette case from his pocket and pulled out a COOL brand mint cigarette from it.

"Captain, the deck is finished, can we begin?" The boatswain shouted from the foredeck to the conning tower.

"Alright, let the boys be in good spirits, now they represent the German submarine forces." Robin replied loudly as he grabbed the conning tower enclosure.

"Got it, everyone! Everyone's in good spirits! The sailor shouted loudly, and the officer on duty on the bridge blew a long whistle. The sailors rushed to their respective positions on the deck, the cannons were opened, the cannons were loaded, and the anti-aircraft rangefinders were mounted on the brackets of the hull fences, and in the blink of an eye, the deck became a solemn look.

The U106 slowly turned its bow and began to move opposite the I-60, at this time only 800 meters between the two sides, approaching a safe distance from the usual sea encounter.

"Stay on course, one-third of the speed." Robin ordered into the intercom microphone.

"It's the captain, one-third of the speed." The navigator replied loudly in the command cabin.

"Send a signal." Robin turned to the signalman and ordered.

"It's Morse code." On the bridge of the Yi 60, Hanafang translated with a telescope.

"This ship... It's the Great Duwills Navy... Submarine ... U106..."

"Oh, it's U106." There was also an exclamation on the foredeck of the I-60.

The group of students of the Naval Diving School, led by the instructors, also ran to the deck to watch the excitement, saying that they wanted to show the young cadets the market, but in fact, several of the instructors who led the team had never seen the German submarines in active service.

"Attention! Such an opportunity is rare, everyone should observe carefully, I saw in the school briefing, this is the ace submarine of the independent navy. Captain Fujiki, the lead instructor, said to the cadets with a serious face, as if he had really seen the briefing.

"The Independence Submarine seems to be preparing for war, are they fighting anyone?" Staff Officer Nomura also heard the news and ran up to the control tower, and the bridge, which was originally quite spacious, was now full of officers of all ranks, and the original sailors had all been driven to the deck.

"How is it possible, the war is long over, Nomura. This should be just ordinary training, and the spirit of never forgetting training is exactly what the Imperial Navy needs to learn, so everyone must work hard, Huafang. Kijima Nakasa looked up at Captain Hanafu.

"Oh, I see, Commander." Hua Fang is still very convinced by this senior who is seven years earlier than him, although the military ranks of the two sides are only one level apart.

In fact, the so-called 28th diving team is currently subordinate to the only submarine, the Yi 60, and the situation of the commander of the team on Guidao can be said to be quite embarrassing.

The original 28th diving team was composed of three submarines, with the port numbers of Yi 59, Yi 60 and Yi 63, all of which were Haida IIIb ocean-going submarines. However, the Yi 59 was subordinate to the Wu Zhen Shoufu in terms of establishment, and it was put into the reserve and sealed just three years after it was launched, so there were only two submarines left in the 28th diving team, and last year the Yi 60 sank the Yi 63, and finally Guijima Moriji Nakasa became the commander of the submarine detachment with only one submarine under his command. If something happens to Yi 60 again, this team can basically be abolished.

"How should the independent submarine ask about the identity, mission and destination of our ship?" Staff Officer Nomura said.

"Reply to them, this ship is the Imperial Japanese Navy submarine I-60, which is on an ocean-going training mission, and its destination is the port of Bangkok in Siam." Guidao ordered to.

"Is that appropriate? Commander. Nomura asked.

"There's nothing to hide in the first place, and you think the Independence will not be found out later?" Guijima was born in a fishing family in Kagoshima and has a very open-minded personality.

The submarine replied, and the U106 sent greetings to our ship, and the captain of the other party ...... Wait a minute... The Solitarians ask us... Is it possible to talk to them... Exchange some supplies?! Hanafang put down his binoculars and looked at the people on the bridge with a surprised expression.

PS: Thank you all for your support, the author will continue to work hard.

Isn't the plot just beginning, and the background is explained clearly, everyone will feel a little more comfortable reading it.