As a part of Update 15, a huge new map was introduced, the Third Sea.
An interactive map of the Third Sea is available here.
Note: since a majority of players set their home point near a portal and the Castle on the Sea is nearly perfectly symmetrical, it is good to know that the mansion (where you spawn) is on the north half of the castle on the sea, in between the two pillars and slightly above the square in the middle (which is the rip_indra room). Also note that the door faces south.
Description
Unlocking the Third Sea
Players can get access to this area by reaching Lv. 1500+, after completing the Colosseum Quest, defeating Don Swan and helping King Red Head subdue rip_indra in the Second Sea. A complete guide to unlocking the Third Sea can be found here.
Spawning
Once the player completes the King Red Head quest, they will then be teleported to The Café. Talk to Mr. Captain at the Green Zone docks near the bridge (or you could use Portal's C and click Docks 3), and you will be teleported to the docks of Port Town. These docks also contain several important NPCS.
Difficulty
The Third Sea is significantly harder than Second Sea. Elemental immunity are somewhat useless due to high requirements needed to gain immunity (reaching up to 100 levels above the NPCs) and the amount of NPCS using Aura. Enemies are spread out more and there are far less islands than the First and Second seas, so more time on each island. The amount of time grinding you spend here is also increased, as you grind 700 levels in the First Sea, 800 in the Second Sea, and 1050 here. The Buddha fruit is recommended grinding in this sea, making it far easier than with Elemental fruits. Be sure to awaken it, as awakening makes it much better for grinding. Expect bounty hunters killing you often and expect them to appear much more often than in the Second Sea. Scripters are often exploiting or stealing kills in this sea, especially in the Haunted Castle and Sea of Treats, so you must be fully prepared while grinding otherwise you will be put at a disadvantage. If you have a private server, it is a major advantage as you will not have to deal with the exploiters and bounty hunters, and also make you able to prevent kill stealing by regular players. It is recommended to get a private server/join a private server in this sea.
Design
The Third Sea is the newest sea in the game, and receives the majority of island updates, so the islands here have far more details and precision than those in previous seas. Something else to note is that the islands in this sea are very far away from each other, presumably to match the far greater movement abilities possessed by those in this sea, so much so that it has its own limited teleportation system, being the Portals, from which you can easily teleport between Hydra Island, Mansion (Third Sea), and Castle on the Sea, but can only be used after killing rip_indra (Raid Boss). The map composes of mainly the Castle on the Sea surrounded by the grinding islands, and sea danger levels beyond.
Valor
Valor 
is a currency found at the Tiki Outpost, in the Third Sea. It is used to level up Shipwright, which can be done by talking to the Shipwright Teacher. Valor is obtained by completing Sea Events, and the harder the Event is the more Valor it gives you.
Subclasses
There is only one subclass in the game so far, and it is the Shipwright, taught by the Shipwright Teacher. If you defeat 50 Sea Events, you can unlock his room. He will reward you with a Legendary Scroll and the Shipwright subclass if you can defeat 20 sharks for him. Shipwright is used to repair Boat health and max health. It can be leveled up by repairing boats and gaining xp. At certain Shipwright levels, you unlock new abilities which make your Subclass more useful, like having more chances of getting Wooden Planks and playing the ship minigame for more health. There will probably be more subclasses in future updates.
Sea Danger Levels
Since Update 20, Sea Danger Levels reside outside of the map of the Third Sea. They vary in levels from 0-6, and the difficulty increases the higher the number is.
List of Islands
Port Town, a small, but rich town where the wealthy gather around to gamble and hang-out with each other. However, behind the town and in the forest, you'll find the ruthless and cold-blooded Stone.
Enemies
- Pirate Millionaire
- Pistol Billionaire
- Stone (Uses Aura, Old version of Bomb Fruit, Boss)
Hydra Island, the legendary island only inhabited by women. These women are snake worshippers. Some warriors can even use their snakes to form bows, allowing them to fire poisonous arrows. As part of the Hydra Tribe's beliefs, men are forbidden on the island. It is also the place to store a rare ancient sword that its owner, a powerful samurai who has been possessed by a demon, has left behind.
Enemies
- Dragon Crew Warrior
- Dragon Crew Archer
- Female Islander
- Giant Islander (Uses Aura)
- Island Empress (Uses Aura and Old version of Love Fruit, Boss)
- Training Dummy (Uses Dark Blade)
- Ghost
Great Tree is a mysterious island belonging to the Marines, notable for its large tree, hence the name. The island consists of Marine Commodores and Rear Admirals, all led by the infamous Kilo Admiral that uses weight and water punches to lead to Marines in this Sea. The reason they are guarding the island is yet to be solved, but one thing is for sure. They are hiding something from us, something rare and powerful.
Enemies
- Marine Commodore (Uses Aura)
- Marine Rear Admiral (Uses Spin Fruit)
- Kilo Admiral (Uses Kilo Fruit, Boss)
Floating Turtle, a metropolis located on the shell of a giant turtle floating on the water, hence the name. Inhabited by Minks of all sorts, it has everything from a giant tree house to pineapple houses to a mansion known for being a Safe Zone for many pirates and marines and a fortress for the-ever-so-lovely, Beautiful Pirate. However, the island has been attacked by the infamous Captain Elephant, hoping to rule it with his army of Forest Pirates. The Crypt Master lives here, guarding a room with 2 scrolls that allow you to master the two cursed katanas. And a mystery surrounds the island: an ancient swordsman has established his hideout in the land, waiting to be challenged.
Enemies
- Fishman Raider
- Fishman Captain
- Forest Pirate (Uses Aura)
- Mythological Pirate (Uses Aura)
- Captain Elephant (Uses Aura, Boss)
- Jungle Pirates
- Musketeer Pirate (Has Flash Step)
- Beautiful Pirate (Has 2nd Form, Boss)
- Longma (Uses Aura, Boss, Drops Tushita)
Castle on the Sea, a Safe Zone and hangout place for many pirates and marines similar to the mansion. It houses the Elite Hunter, who tracks down Elite Pirates abusing their awakened Blox Fruits, wreaking havoc on islands, the Player Hunter, who tracks down players and requests the player to take them down for some sweet rewards; a Butler who knows everything about the Third Sea and gives hints about the puzzles that await you; Lunoven, who hates Elite Pirates for an unknown reason; and every Fighting Style teacher from past seas have ventured here to teach more powerful students. It's also a place where many pirates from all across the sea to raid the castle. Three plates are scattered across the island and when activated allow you to place the ancient chalice held by God himself. By placing it on a platform in the main section of the castle, you've made a terrible mistake of summoning.... him...
Enemy
- Rip indra (Raid Boss, has 2nd Form)
Haunted Castle, a large boat often mistaken as a castle due to its enormous size, is inhabited by deadly supernatural blood-thirsty zombies and Berserk skeletons. This boat's currency is bones, and if you defeat the island's residents you may collect a few of them yourself, and buy random suprises, including fire in it's purest form, All are led by the evil Soul Reaper, who awakens with the trigger of the Hallow Essence. A powerful fighter said to wield fire in his fists is rumored to be camping at this island, but not many people know his location.
Enemies
- Reborn Skeleton
- Living Zombie (Uses Aura)
- Demonic Soul
- Possessed Mummy
Sea of Treats, a mini-sea that consists of 5 separated islands. The islands are all food-based and contain Peanuts, Cookies, Ice cream, and so much more! But unfortunately, they are all conquered by the ever-hungry, Cake Queen. Here you can meet a guy, who would ask you to defeat 500 Cake Land NPCS near him for a portal to spawn that would lead to a dimension where Cake Prince resides, or alternatively give him a Sweet Chalice crafted by Sweet Crafter, combining the ancient God's Chalice and 10 Conjured Cocoa to spawn in the hardest foe you will face... The Dough King.
Enemies
- Peanut Scout
- Peanut President (Uses Aura)
- Ice Cream Chef
- Ice Cream Commander (Uses Aura)
- Cake Queen (Boss)
- Cookie Crafter (Uses Aura)
- Cake Guard (Uses Aura)
- Baking Staff (Uses Aura)
- Head Baker (Uses Aura)
- Cocoa Warrior (Uses Aura)
- Chocolate Bar Battler (Uses Aura)
- Sweet Thief (Uses Aura)
- Candy Rebel (Uses Aura)
- Candy Pirate (Uses Aura)
- Snow Demon (Uses Aura)
Tiki Outpost is an island famous for explore and hunting sea events, and is surrounded by continuous rainy weather. This island has a secret basement, inside there you can found a powerful person who can teach you a Fighting Style with the power of darkness and blood. This island also has a mage, believed to be a sage of Uzoth the teacher of Dragon Talon, residing here, he can help you enhance the powers of your weapons. There is a shipwright who can teach his skills to you, a crafter of the monster-slaying weapons and a crafter of shark-slaying weapons, who are the traders here. At the top of the temple, you can find Spy, who is looking for a giant serpent with the power of ice and water, awakened by King Red Head.
Enemies
- Isle Outlaw (Uses Aura)
- Island Boy (Uses Aura)
- Sun-kissed Warrior (Uses Aura)
- Isle Champion (Uses Aura)
Trivia
- This sea holds the title of having the least number of islands (8); however, more are to come. It also could be counted as 12 islands as there are several mini islands in the Sea of Treats or 16 if Mirage Island, Kitsune Island, Treasure Island and Frozen Dimension are included.
- Some Easter Eggs can be found in this sea.
- After Ice Cream Land (Sea of Treats), all of the enemies use aura, nullifying elemental immunity even if you surpass the required level.