Grand Line

The Grand Line (偉大なる航路（グランドライン）) is an ocean within the world of Hedgehog Piece.

The Grand Line is the ocean current that is surrounded by the Calm Belts and follows an imaginary line that runs from North to West to South to East across the middle of the world and perpendicular to the Red Line. The Red Line is a vast continent that circles the globe from North to East to South to West. These two lines divide the rest of the Blue Sea into the Blues: North Blue, East Blue, West Blue, and South Blue. This stretch of ocean is said to be the most dangerous place in the world, and is commonly referred to as the Pirates' Graveyard by people from the four Blues because of this reputation (But referred to as "Paradise" for those few who make it to the second half, showing it is all relative). Most believe that it is impossible to safely leave the Grand Line save at its beginning and end; however, the World Government regularly sends ships across the Calm Belts by coating their hulls with Kairoseki, rendering them invisible to the Sea Kings. The Grand Line is placed similar to the equator.

Calm Belt
To the north and south of the Grand Line are strips of ocean known as the "Calm Belts". The true entrance to Grand Line is usually marred by storms; the waters of the Calm Belts remain static year round, and there are virtually no winds or waves (this makes it difficult to cross without propulsion). Extremely large sea monsters called Sea Kings live in the Calm Belts; in fact, the monsters found in the Calm Belts are the largest known. The combination of no currents, no wind, and the presence of the Sea Kings makes these belts perfect barriers to any traveler trying to directly go into the Grand Line.

Without using Kairoseki-lined ships (which are concealed from the Sea Kings to a certain degree) and some propulsion, the Grand Line can only be accessed at two points on the Red Line: Reverse Mountain and the Holy Land of Mariejois. The first is where the four major currents of the Blues merge together to form the Grand Line, while the second is the site of the World Government.

Halves
The Grand Line is divided by the Red Line into two halves. The first half, stretching from Reverse Mountain to the polar opposite point of the Red Line, is known as Paradise. The second half, which starts beyond the second Red Line point to the backside of Reverse Mountain, is known as the New World.

Paradise
The first half of the Grand Line is known as Paradise (楽園（パラダイス）) to those who have been to the New World. It lies between East Blue and South Blue. While the Grand Line is a dangerous place, the first half is known as such in comparison to the more terrifying dangers present in the New World.

New World
The New World (新世界) is the second half of the Grand Line. It lies between North Blue and West Blue. This half has not been fully explored. This area is also where the Yonko reign.

Climate
The weather is unusual on the Grand Line. The currents and weather are extremely volatile, as they can change in an instant; this includes water spouts, storms, blizzards, and other such things. Islands and the surrounding waters are the only areas where weather and currents are stabilized in a predictable manner. The reason for this is that islands on the Grand Line fall into four basic categories: Winter, Spring, Summer, and Autumn. These types of islands each have four seasons of their own, giving the Grand Line a total of 16 different seasons.

There are also cyclones that seems to appear quickly and suddenly.

Navigation
Normal compasses do not work on the Grand Line because of the nature of its magnetic fields. In order to navigate the Grand Line, a special compass called a Log Pose must be used. The Log Pose works by locking on to one island's magnetic field and then locking on to another island's magnetic field. The Log Pose can do this for a total of seven different routes that diverge from Reverse Mountain and travel east before merging again to the last island. The time for a pose to set depends on the island. One island may take from a few hours to a few days to set to the next island, while another can take a year to set. This process can be bypassed by obtaining an Eternal Pose. This version of the Log Pose is permanently set to a specific island and can never change. This makes it easier for a crew to get to a specific island rather than going through a trail of islands.

It has been noted before that small sea vessels such as caravels do not make it particularly far in the Grand Line. Despite a crews best efforts it is difficult to keep a ship in good condition and avoid it getting battered by the Grand Lines natural hazards and only good quality ships with knowledgeable crews stand a chance of traversing it safely.

Paradise
Known have been revealed/talked about throughout the story of Hedgehog Piece.

New World
Known have been revealed/talked about throughout the story of Hedgehog Piece.

Paradise
No characters are known or have been revealed to be from this part of the Grand Line as of yet.

New World
No characters are known or have been revealed to be from this part of the Grand Line as of yet.