XL Ocean

The XL Ocean is an advanced version of the Ocean and can be found in a world with a 1 in 1.5% chance of occuring instead of 2 oceans. The XL Ocean is div into four segments/zones. Each of them existing in real life.

Zone 1 (Easy)
The Sunlight zone isn’t a challenge and can be utilized for pre-hardmode and hardmode. In the Sunlight zone, Jellyfish, Sharks, And Orcas will spawn. In Challenger Mode, Sharks can drop water Water walking boots (10% chance) or Breathing reeds (20% chance if Water walking boots don’t drop) and rarely the beach ball (0.5% Chance)

Zone 2 (Medium)
The Twilight zone should be utilized for Post-Plantera. Illusive Sharks, Man o' Wars in Warmode, Death Dolphins, and Octopuses can spawn here. It’s risky to go here during the mechanical bosses but loot that shouldn’t be intended for example, The Aquatic Revolver could clear out the remaining mechanical bosses.

Zone 3 (Hard)
The Midnight zone can randomly spawn the Colossal Squid so the player should only enter the third zone in warmode. Doing so in Post-Moonlord can be very dangerous. The rest of the enemies that spawn here depend on which evil biome you have. Here’s a table to simplify it. The last 2 are mini-bosses. For The Haunted there’s the Possessed Pirate, The Infected Dolphin, and the Lunumfish. For the mini-bosses, there’s the Fighter Shipwreck and the Storm from below.

Zone 4 (Extreme)
The Abyssal zone has the first epilogue boss, that being The Abyssal Horror. The Sharkruptor has a 1% chance of spawning here when daytime hits and the player is in the biome. The Abyssal zone should only be entered during The Epilogue. The Cruelity Kelp and The Strict Seaweed spawn down here along with a miniboss determined on which one is closest to the biome.

Resources:
Sea Spores (Zone 4)

Octopus Tentacle (Zone 2)

Squid barnacle (Zone 3)

Aqua Shard (Zone 1)

Shark fin

glowstick

Trivia

 * The XL ocean has a 1 in 20000% chance of accuring twice instead of just once.