On the fifth day after leaving the port of Pola, U-21 finally arrived near the island of Malta. However, Captain Hesen did not rush to dive into the Malta Channel to search for prey. Instead, he waited quietly in a remote location away from the shipping lanes. It wasn't until the sun began to set that he ordered U-21 to carefully make its way towards Valletta, the most important port on the island of Malta.
As the black silhouette of Malta appeared at the edge of the sea, the sky was gradually darkening. At that moment, standing on the submarine's conning tower, Captain Hesen commanded:
"Everyone back inside the hull, ensure all watertight doors are closed, and be ready to dive at any moment!"
In no time, there was not a single soul on the submarine's deck, not even the first mate Wolff. Everyone had retreated inside the vessel. Only Zhang Hainuo and Hesen remained on the conning tower, both wearing black rain capes resembling cloaks. Each held a pair of high-powered binoculars, scanning the sea surface incessantly.
Most of Zhang Hainuo's impressions of Malta came from the series of naval and aerial battles fought around the island during World War II. Like many military enthusiasts, he believed that the Axis powers' failure to capture Malta was a strategic mistake. Malta was a crucial transit point on the Mediterranean route, just a sea away from Sicily, Italy. The supply difficulties faced by Rommel's Afrika Korps in North Africa, which contributed significantly to its eventual defeat, were largely attributed to the interception of Axis ships by British aircraft, submarines, and warships, many of which operated from bases in Malta!
When a gray dot appeared in the binoculars, Zhang Hainuo nudged Hesen with his elbow.
"Captain, there's a ship over there, but I can't tell if it's a freighter or a warship!"
Hesen glanced in that direction. "Don't worry, it's a British gunboat. Its duty is to patrol near the harbor and generally doesn't venture this far out. Besides, we're currently out of its observation range!"
Based on Zhang Hainuo's rough estimation, they were still at least 15 nautical miles from Valletta Harbor, and the ship appeared to be about 10 nautical miles away. But how could Hesen determine it was a gunboat from that gray dot in the binoculars? His binoculars didn't seem to have higher magnification than Zhang's!
Perhaps that's the difference between a novice and an old hand! Zhang Hainuo thought to himself, hoping to reach that level someday.
"Halve the cruising speed!" Hesen shouted into the voice tube, seemingly unconcerned about his voice reaching the ears of the British on the island.
Reducing the speed from full to half wasn't just about the submarine's surface speed; it also reduced the noise generated by the two diesel engines. In an era with radar and advanced sonar equipment, Zhang Hainuo found it hard to imagine a submarine like U-21 approaching an enemy port in such a calm manner on the surface. But this was 1917, an era when anti-submarine warfare technology was far from advanced.
After about fifteen minutes, Zhang Hainuo and Hesen almost simultaneously spotted a ship approaching from the east.
"A freighter, with a displacement of about 2,000 to 3,000 tons!" Once again, Hesen demonstrated his extensive maritime experience, as Zhang Hainuo saw nothing more than a white "little boat" through his eyes!
"Change course to 340 degrees, full speed ahead!" Hesen commanded through the voice tube.
Was it time to prepare for an attack? Zhang Hainuo felt a rush of excitement. This would be his first time attacking a target alongside a submarine. Without any escort vessels, the unlucky freighter shouldn't be able to escape Hesen's grasp!
The winter night fell early, and soon the sea surface was completely dark. This reminded Zhang Hainuo of a classic line from a movie: "The moon is dark and the wind is high, a night for murder."
At this moment, lights began to twinkle on Malta, especially the tall lighthouse at the entrance of Valletta Harbor, visible from a great distance.
Are the British so bold that they don't even enforce light restrictions during wartime? Zhang Hainuo found it strange. Wouldn't turning on such blatant lights serve as a beacon for enemy submarines?
Seemingly sensing Zhang Hainuo's doubt, Hesen explained that despite the bright lights of Valletta Harbor, the waters outside were heavily mined and protected by anti-submarine nets. Every merchant ship entering the harbor required pilotage from a tugboat inside the harbor. It was not only risky to infiltrate the harbor but also dangerous to approach it. Moreover, the harbor housed several British cruisers and a full squadron of British destroyers. It wasn't easy to attack British ships near the harbor and escape unscathed. Hence, German submarines deployed in the Mediterranean mostly ambushed near the Malta Channel, rarely venturing into the strait itself.
In the end, it was the limitation of batteries that could only sustain submarine operations for a little over an hour that created this tactical "bottleneck"!
"What about today..." Zhang Hainuo glanced at the brightly lit ship ahead on the sea, realizing that attacking it in the strait would likely result in being pursued by a squadron of British destroyers.
Hesen glanced at him meaningfully, offering no response.
After changing course, U-21 quickly moved to the position between the arriving freighter and the harbor. Zhang Hainuo had learned in naval school that this was called seizing the attacking position—laying an ambush in front of the ship's course and launching torpedoes as it approached, unable to match the speed of surface vessels.
Before long, the ship turned on a searchlight, and a small boat appeared from the direction of the harbor—the pilot boat that Hesen had mentioned.
"Dive!" Without warning, Hesen suddenly gave the order to dive.
Since the incident where Hesen "played" him, Zhang Hainuo had been silently practicing how to descend from the conning tower into the hull and close the watertight hatch as quickly as possible every day. He even consulted Otis for advice. Although he dared not claim to be better than other crew members now, he was no longer as clumsy as he was at the beginning.
However, this time, Hesen didn't ask Zhang Hainuo to take the rear position but personally took the lead.
Before Zhang Hainuo had taken more than two steps after descending from the vertical ladder, Hesen also came down with a thud, clearly sliding down the ladder.
"Very fast!" Zhang Hainuo thought to himself. If it were him, he probably wouldn't have closed the watertight hatch by now!
"Dive to periscope depth! Full speed ahead!" Hesen quickly walked to his command station.
Hesen rarely looked at his watch; he seemed to have an innate sense of time. Five minutes later, he commanded, "Raise the periscope!"
A cylindrical object slowly descended from the top of the conning tower. To maintain consistency with the outside light, all wall lamps inside the hull had been switched to dim red. Zhang Hainuo felt like he was in a movie, yet everything here was incredibly real.
Hesen grasped the handles on the periscope with both hands, his eyes tightly pressed against the viewing mirror, his body moving with the periscope's rotation. Zhang Hainuo stood opposite him, his eyes fixed on the scale indicating angles on the periscope.
Soon, the periscope stopped rotating, and Hesen straightforwardly asked Zhang Hainuo, "Angle?"
"328!"
"Target 1, angle 328, distance 10,600!"
After that, Hesen rotated the periscope clockwise a bit more. "Angle?"
"057!"
"Target 2, angle 057, distance 14,200!"
After reporting this string of data, Hesen closed the rotating handle of the periscope. "Retract the periscope!"
Hesen briskly walked to the navigation table, where the navigator, Loqi, had prepared a monochromatic chart with only lines and no colors. Zhang Hainuo leaned over to take a look. The chart depicted a corner of both Malta and Sicily, but apart from outlining the contours of the islands and a few ports represented by small circles, there were no enemy ships, troop deployments, or underwater topographic maps. This was far from the military maps people imagined; it was essentially a two-dimensional map not much different from a hand-drawn scroll.
It seemed that the lack of reliable charts and intelligence was one reason why German submarine captains were reluctant to "hunt" near Malta!
However, Hesen paid no attention to Zhang Hainuo's thoughts at this point. He busily worked with a pencil, ruler, and compass on the rudimentary chart, annotating the entire battle plan with lines and numbers that only he could understand.