The “One Piece” manga series refers to the Grand Line as the “Red Line”. The anime has been retconned to use the name “Grand Line” instead.
The Grand Line is an ocean route that is only possible to cross due to the likelihood of having the King of the Sea as a navigator. It is not just one sea, but rather many that span from East Blue to West Blue.
Anyone can theoretically enter the Grand Line, but it is dangerous because there are unpredictable weather changes and sea monsters (Sea Kings) along with other threats such as pirates. If one manages to get past these obstacles they may become part of what’s known as Pirate King: an extremely prestigious position reserved for only those who have conquered this treacherous road.
Along the Grand Line, there are four different seas, each with its unique climate. The first sea is called Calm Belt; the second is called Paradise; the third is called Fish-Man Island, and the last one is called New World. The weather conditions of each sea change due to different reasons.
Also, many pirates are leaving East Blue (the easiest sea) and going on to other seas to make bigger and better names for themselves as they get stronger by winning fights against powerful opponents.
Climate and Weather of Grand Line
The climate of Grand Line changes drastically from one sea to another. The climate of each sea is determined by its relative location on the map, which means that the climate changes from one island to another (like going south to north).
In One Piece anime, the extent of the change in climate from one sea to another can be seen from the wide range of clothing and housing styles when one crosses over from East Blue to West Blue. It can also be seen that the climate of Fish-Man Island is most tropical, or close to tropical climates. However, there are still many islands in West Blue that have a cooler climate than those on Fish-Man Island.
The weather changes drastically from island to island and sea to sea. The entry point between East Blue and West Blue is judged by a person’s strength (although not stated so explicitly).
Pirate King or Pirate King of the Sea refers to an elite group of individuals who have conquered all four lands, and are considered to be the strongest of all pirates.
The Monkey D. Luffy, after becoming the Pirate King, has become one of the most powerful pirates in history. He is one of only sixteen Pirate Kings who has achieved this status.
Zoro and Nami were raised on Roronoa Island (the first Amazon Lily) by a pirate named Shirahoshi and her family.
Islands in Grand Line in One Piece Anime: Sea Monsters of Grand Line in One Piece anime :
There are various types of sea monsters (named Sea Kings), but when mentioning them it is often said that there are four in total.
Navigation at Grand Line Ocean
A normal compass won’t work on the Grand Line due to the vast amount of air disturbances. The Navigator’s Compass helps the navigator to find his way. The navigator’s compass is used to keep himself updated with the current maps. Also, due to different magnetic fields, the compass stopped stop working and there is only one compass made for navigation. The name of that special compass was Leg pose.
Leg Pose works by pointing to the sky and holding one leg up in the air. Like a normal compass, it will show directions but only in one particular direction (North or South in this case). Due to its limited usage on Grand Line, some pirates do not carry such a compass with them.
However, during the time skip one of “Twice” Shanks Pirates Crew had modified the leg pose by placing a glass globe filled with water over their head and pointing their leg towards the north. This new navigation method is dubbed as “reverse pose”. The modified version can be used without pointing at the sky and makes navigation easier for these pirates.