August 11, Sea Circle Calendar 1504.
Starfish Island, where the Noah Family had gotten its start.
The family still maintained a few small businesses on Starfish Island. At this moment, Noah brought Ray back to the island through a wormhole jump.
But the two did not stay on Starfish Island for long. Soon, they would secretly pilot the Nautilus to the Red Line.
In fact, the entire Polestar Islands lay next to the Red Line. At their closest, the two were less than seven hundred kilometers apart.
The reason Noah and Ray were heading to the Red Line was to reach the North Blue.
In fact, traveling from the East Blue to the North Blue was relatively easy. Only the Red Line separated the two seas, and the Vinsmoke Family would later use giant snail ships to climb straight over the Red Line into the East Blue.
To reach the South Blue or the West Blue, however, they had to pass through Reverse Mountain's skyward canal-and travel against the current, making it extremely difficult.
Of course, any force capable of crossing the Red Line was formidable in its own right, or at least no ordinary force.
After Noah and Ray reached the nearby Red Line, they looked at the red cliffs towering into the clouds and the white ice and snow atop the Red Line. They knew that crossing this plateau, over ten thousand meters high, was far too difficult for ordinary people.
But Noah did not need to cross over the Red Line.
The two spent more than a week circling the nearby waters before finally finding several suitable locations.
At each of these locations, the waters beneath the cliffs were extremely dangerous.
The Tidal Sea, the Great Whirlpool Section, and the Ghost Reef Bay Section were the most dangerous of all. If Noah and Ray had not been so strong, they might not have made it safely through those waters.
After surveying and weighing their options, Noah chose the Tidal Sea, the most dangerous yet relatively secluded of the locations.
The Tidal Sea as a whole was shaped like a funnel.
At high tide each day, seawater poured in continuously from the open sea. As the waves drew closer to the innermost end, they grew higher and higher, even exceeding a hundred meters during astronomical spring tides.
At low tide each day, the water level in the Tidal Sea dropped rapidly, exposing many submerged reefs and turning the area into a reef field that was difficult for ships to navigate.
Noah and Ray abandoned the idea of piloting the Nautilus in and instead relied on their own abilities to reach the innermost end of the Tidal Sea.
Waves had battered the cliffs here for ages, leaving them riddled with holes, somewhat like the cliffs on Sikasis Island.
That was also why Noah had chosen this location.
Although Mary Geoise was the central section of the Red Line where the World Government stationed its forces, that did not mean it left the other sections unmonitored.
If a cave suddenly appeared in the Red Line's cliffs, the World Government's patrol ships could easily spot it.
But patrol ships never came to the Tidal Sea, and its cliffs were already covered in caves eroded by the waves, providing excellent natural cover.
The two found a suitable cave and began building a secret passage.
Using the Hole-Hole Fruit's power, Ray quickly excavated a tunnel into the cliff before him. The excavated rock was sent straight through a wormhole into a nearby sea trench. This was also the basic principle behind using the Hole-Hole Fruit to excavate caves.
The Red Line was enormously wide, reaching more than five thousand kilometers at its widest and no less than one thousand kilometers at its narrowest.
The stretch between the Tidal Sea and the North Blue on the other side was approximately 3,200 kilometers wide.
The excavation route would not necessarily be straight, either. Noah did not yet know what the waters on the other side were like, and if they happened to be calm, they would have to adjust the route.
Ray dug very quickly.
With his stamina, he could dig for about three hours straight. The tunnel had a cross-sectional radius of approximately fifty meters, and Ray could advance about ten kilometers an hour.
In other words, he could dig thirty kilometers of tunnel each day.
At a width of 3,200 kilometers, it would take about 107 days.
Noah did not remain idle either.
Although the tunnel had been dug, that did not mean it could be put to use immediately. Air circulated very slowly inside such a long tunnel, and there might even be a risk of suffocation.
If they could expand the tunnel's cross-sectional radius to around one kilometer, that would solve the problem.
Unfortunately, a cross-sectional radius that large would not only make the tunnel easy to discover, but could also destabilize the surrounding rock strata and cause a large-scale collapse.
Noah therefore had to choose another compromise.
He would build an oxygen tank storage room on one side of the tunnel at regular intervals, supplying passing family members with oxygen tanks. He could even store some fresh water and food in them.
To speed up travel, Noah also laid two stone tracks for electric trains to run on at high speed.
These facilities and the tunnel were actually for ordinary family members. After all, Noah had cards in which to store supplies, and Ray could use wormhole jumps, so neither of them needed the supply stations inside the tunnel.
Even with Ray available, they went to the trouble of building this secret tunnel as a precaution. If, for example, Ray suddenly died or was temporarily unable to provide support, the family could use the tunnel to travel quickly between the East Blue and the North Blue.
Noah had actually prepared several similar backup plans.
After all, it paid to be prepared. If they waited until trouble was upon them to find a solution, the consequences could be severe.
That was a situation Noah had always tried his best to avoid.
With the base in the Tidal Sea cliffs initially complete, Ray also left a semi-permanent wormhole coordinate point there.
At present, Ray could maintain a maximum of eight Wormhole Coordinates in total.
He had placed one at Rum Base in the Rum Kingdom, one at Ant Nest Base on Sikasis Island, and one at the bottom of a great sea trench near the Rum Kingdom. Together with the one at Tidal Base, that made four fixed Wormhole Coordinates in use.
The remaining four Wormhole Coordinates were for Ray to use in combat and everyday travel.
Inside Tidal Base, besides the Wormhole Coordinates Ray had established, there were self-destruct devices Noah had secretly installed, as well as various defensive facilities.
More than three months passed before they knew it.
After over a hundred days of continuous work, Ray finally dug his way close to the cliffs on the North Blue side.
Ray did not immediately dig through the remaining kilometer or so of rock. Instead, he chose to excavate a small passage just large enough for one person to pass through.
Ray soon dug through the rock, but he was very careful, opening only a small crack and observing the surrounding waters closely.
The opening was in the cliff about 150 meters above sea level, and the surrounding sea was extremely calm. This greatly disappointed Ray, because such calm waters were not suitable for an exit.