A single German G7 torpedo, loaded with 195 kilograms of mixed explosives, would be enough to blow up a barge or a patrol boat, but the first ship Zhang Hainuo attacked on the east coast of the United States was not only large in tonnage, but also likely not carrying heavy cargo. Therefore, it took over two hours for it to slowly capsize after being hit by the torpedo.
After completing the attack, Zhang Hainuo and his U148 did not retreat far away. Instead, they lurked quietly beneath the surface not far from the American cargo ship, observing everything that was happening.
This was the best way to find out about the American alert situation in this sea area.
The situation observed by Zhang Hainuo was good news for the German Navy's ocean-going submarines. The long-term isolation, absolute military advantage in the Americas, and geographical distance from Europe made Americans lax in guarding their coastal areas even a year after entering the war. It took nearly an hour for two small coastal patrol boats to arrive from the harbor after the cargo ship was hit by a torpedo. Their searchlights were on, but they focused not on the sea surface but on the stricken cargo ship. Then, two unarmed barges arrived, not to rescue people, but to pick up whatever the sailors threw off the ship!
An hour and twenty minutes later, a slightly larger American destroyer came slowly from the north. By this time, the fire on the cargo ship had basically been extinguished, but the influx of seawater from the huge breach caused by the torpedo was too much. The cargo ship had tilted more than 30 degrees to the right, and it was on the verge of capsizing. The sailors hurriedly evacuated.
As the cargo ship went from severe tilting to ultimately capsizing, the last arriving American destroyer did not rescue people or search for the perpetrator. Instead, like U148, it acted as a faithful spectator. U148's lurking was understandable, but the behavior of the destroyer, moving at a slow speed in an area where enemies might appear, seemed amateurish. It repeatedly entered U148's firing position. If Zhang Hainuo hadn't been reluctant to waste precious torpedoes on such a thousand-ton destroyer, he would have sent it to the bottom of the sea with a torpedo long ago!
When the cargo ship finally disappeared from the surface of the sea, the sky was gradually brightening, but the light rain had not stopped yet. The sea surface remained gray and misty, allowing U148 to watch the departing American ships underwater, before calmly surfacing.
Perhaps this was the cleanest battlefield Zhang Hainuo had ever seen. Apart from some floating debris and oil stains from the explosion, the two American barges took away everything valuable before leaving. However, this also led Zhang Hainuo to speculate on another possibility besides German submarines laying mines or torpedoing American ships in this area: the US Navy might also have laid mines in this sea area!
Thinking of this, he was glad he hadn't rashly approached the port last night. By now, he could clearly see the coastline more than ten nautical miles away. The tall lighthouse still stood at the junction of land and sea, behind which could be vaguely seen a large port city.
When he saw the orders from the Navy and the poor-quality nautical chart, Zhang Hainuo thought of a risky plan. He carried two radios with him. When the sailors were on alert, he turned on the radios and tuned them to the medium-wave band.
After some interference, a relatively clear voice came from the radio.
Most German sailors had no idea what was being said in the "bird language" inside, but fortunately, Zhang Hainuo, Staff Officer Otto von Glennburg, and First Officer Simon understood some English. The three of them gathered around and listened while trying to understand. American English and British English had pronunciation and habit differences, and some slang made it difficult for those who hadn't learned American English separately to understand. Fortunately, the announcers on radio stations, especially news programs, spoke much more standardly. Eventually, they locked onto a station with relatively good volume in the medium-wave band. By noon, it began broadcasting news.
(Author's Note: The United States passed the Radio Act in 1927 and established corresponding management organizations. During the war, although there was some news censorship, radio stations could still broadcast news with government permission.)
After skipping over news about economics, politics, and the European war situation, Zhang Hainuo and his crew finally heard a very valuable piece of news:
"At around three o'clock this morning, the American cargo ship 'Owl,' carrying textiles to Brazil, sank after hitting a mine a few nautical miles outside Boston Harbor. The preliminary investigation by the Navy Department indicates that the vessel, named 'Owl,' accidentally struck a naval mine previously laid by the Navy. The Navy Department hopes that citizens do not panic and do not believe rumors about German submarines. Ships entering and leaving the harbor should navigate through the channels designated by the Navy Department to avoid encountering the Navy's defensive minefields! Currently, all crew members of the 'Owl' have been rescued. A Navy Department spokesperson stated that they will determine whether compensation will be provided to the shipowner and crew after further investigation!"
"Boston, we are now approaching Boston, the largest commercial port in the northeast United States!"
Young Glennbrook exclaimed with joy, surrounded by the crew who gathered around.
"The vessel we sunk this morning was a cargo ship carrying textiles to Brazil!"
Zhang Hainuo's voice was evidently more composed. Despite his words, there was not much pessimism on his face. After all, in the extreme lack of intelligence, it was difficult for him to speculate on what goods were inside the ship and where the ship would go. Exchanging a torpedo for a ten-thousand-ton vessel was a good deal from any angle.
Moreover, this seemingly insignificant event had indeed yielded a series of invaluable information.
"Lieutenant, what's our next move?" Simon's words prompted everyone to turn their attention to Zhang Hainuo.
"We'll continue lurking here during the day, trying to learn as much as possible about the routes of American merchant ships entering and leaving the harbor. When night falls, we'll go out to lay mines on their routes! And then..." Zhang Hainuo furrowed his brow, staring at the somewhat incomplete sea chart, pondering for a moment. After calculating the distance, voyage, and time in his mind, he continued:
"We'll head to New York to try our luck!"
New York's status in the United States was equivalent to that of Hamburg in Germany or Liverpool in the UK, both important economic centers and commercial ports of their respective countries. After entering the 20th century, New York's level of economic development was unmatched by Hamburg or Liverpool. Just thinking about the accolades awaiting them, the crew seemed to have envisioned the medals hanging from their chests.
Over the next two days, U148 surfaced only two to three times during the day, and at night, guided by the lighthouse, quietly approached the shipping lanes outside Boston Harbor to lay mines. Zhang Hainuo, using the boat's twelve mines, set up two small minefields, one about 9 nautical miles from the lighthouse and the other further away, both positioned near the shipping lanes but not directly in the center.
After that, Zhang Hainuo commanded U148 to sail southwest. He didn't need to wait outside Boston Harbor anymore because the American radio stations would transmit the battle report to him as soon as possible.