In later generations, there are many TV series and movies, all of which depict the spectacular world war and submarine warfare movies, which are also endless.

And in order to attract the attention of the audience and exaggerate the gripping tension, there is a bridge where the submariners cannot speak loudly on the submarine, and as a result, a coin is accidentally dropped.

And the most godly, the sonar of the other party, actually heard whether it was face down or tail, this definitely belongs to the category of divine drama.

In this era, of course, it is impossible to happen, and even in later generations, sonar technology is already quite advanced, it is impossible to reach this level.

Sonar technology, in fact, has been available for a long time, much earlier than radar, after all, sonar is equivalent to receiving sound, amplifying sound, simply put, isn't this function realized by microphones?

However, in order to be used on submarines, this large microphone must be more refined, and at the same time, the amplification ability must be as powerful as possible.

For example, on this submarine of the island country, it is equipped with the latest Type 93 hydrophone developed by the island country, yes, now it is not called passive sonar, it is still called a hydrophone, and this name is more vivid than sonar.

As for its effect, some data say that it can only be heard at a distance of about a hundred meters? (East China Zhixiong is not sure, I hope to know greatly to solve the doubt.) ）

The sailor dog head Rokuro has a big black headset on his head, and in front of him, the cathode ray tube is also erratic.

Suddenly, his brows furrowed, and his face became extremely pale: "Captain, I heard the sound of depth charges falling into the water, well, there are still a lot of them!" ”

"Dive, keep diving!" The ghost head deflated three ordered.

Now, they're traveling underwater at a speed of 3 knots, which allows the precious power to last longer, but the disadvantage is that they can't get out of the sea quickly.

And now, the anti-submarine deep bombs one by one show that the opponent's interception force has arrived!

Up to now, the ghosts are wondering, why do these Americans beat them when they catch them? Didn't you have a conflict with the Americans?

"Boom!" At this moment, an anti-submarine deep bomb exploded in the water overhead, and this huge sound made Gotou Rokuro immediately close his eyes in pain and take off his earmuffs vigorously.

He felt his ears, almost bleeding, rumbling inside, this is definitely not a good experience, don't believe it, what would it be like if you magnified the sound of the shell explosion a hundred times to the side of your ear?

The sound was very loud, this bomb exploded near the submarine, and the sound wave slapped against the shell of the submarine, which has a cavity effect of amplifying the sound for the cavity of the submarine.

Hiding inside a submarine will not give you a sense of security.

"Dive, keep diving!" The ghost head is still experienced, and although the sound of this explosion is terrifying, it will not cause harm to the submarine.

It's not scary to hear an explosion, it's scary to hear the sound of water under high pressure, because that means the submarine has already broken a big hole!

At his command, the submarine began to tilt.

The propeller in the tail turned slowly, and the hull of the submarine, tilted, headed deeper into the sea.

"Set to a depth of 100 meters." The ghost head shouted.

His words made others tremble suddenly, and the helmsman in charge of the operation turned his head and looked at him with uneasy eyes.

This Haida 6B submarine is an improvement on the basis of Haida 6A, and the improvement is to increase the diving depth and increase the range.

However, even if it is increased, there are limitations, for example, the design depth of this submarine is only 85 meters.

In the ocean, the pressure of the sea water is the terrible enemy, every ten meters of diving, it is necessary to reduce the pressure by about one atmosphere, the pressure shell outside the submarine, there is a limit, if the design depth is exceeded, God knows what will happen.

"Execute the order!" The ghost head said deflated.

As an old submariner, at this time he was clear.

The design depth is the design depth, the actual depth is the actual depth, and there is a margin when designing.

What's even more terrifying is that his submarine can't outrun those terrible enemies on the water, even if he sails at a speed of 3 knots, at most 65 nautical miles, it will reach the limit.

Once the battery is exhausted, he needs to surface to charge the battery, and when the time comes, can he still run away?

This attack is too strange, he needs to persevere, hold on until there is action at the top, this is his hope of being rescued.

Is there anything more important than adding depth?

The ghost head is also deflated, and there is no choice.

The submarine was slowly sinking, and the helmsman was looking at the depth gauge, sweat constantly oozing from his back.

Finally, at 95 meters, he began to slowly flatten, and finally, the submarine stabilized to a depth of one hundred meters.

"I've dived to a hundred meters." The helmsman said.

Picking up his headphones again, Kotou Rokuro continued to listen to the sound inside, and by this time, the sound had become quieter.

"The deep bomb also exploded at a depth of twenty meters, and it had no effect on us." Kotou Rokuro shouted.

If it is on a warship, when the warship encircles and suppresses the underwater submarine, it can be adjusted at any time, and it can be changed at any time before the anti-submarine depth bomb falls into the water.

However, the deep bomb carried by the plane is not good, and no pilot can do aerial acrobatics, go to the wing or belly to readjust, and when it is loaded, it has already been determined.

The small bombs on the wings have a fixed depth of twenty, while the large bombs under the belly have a fixed depth of one hundred.

If the German submarine is at periscope depth, then 20 meters is just right, if the German submarine dives, their diving depth is more than 100 meters, set to 100 meters, relying on the power of the big bomb, it can still be exploded.

When the first overlay bombing was completed, all the planes had risen in altitude, leaving only the seaplane, still watching.

If the submarine below is blown up, there will definitely be a bigger explosion, there will be oil stains, and corpses will float up, so that the results can be confirmed.

The Kingfisher reconnaissance plane flew around the sea and flew around and around, and Chris and Schroeder observed the sea surface repeatedly, but no abnormal situation appeared.

"That submarine must still be hiding underneath!" The captain of the bomber shouted: "Prepare to drop a big bomb!" ”

The small bombs have been dropped, and now, there are only big bombs left, and since nothing has been blown up, let's just go to the big guys!

In the sky, dreadnought bombers, again lined up in formation, swooped down.