Paper Mario: The Origami King - How To Find Diamond Island | The Great Sea Walkthrough

The Great Sea is the most open-ended area of Paper Mario: The Origami King yet! That makes it even trickier than the Scorching Sandpaper Desert. You’ll have to thoroughly explore the massive map with your boat, map out all the islands you can find, and discover the lost locations of an area called Diamond Island. Finding Diamond Island isn’t easy, so let’s find the location together.

There’s a few things you need to know about the Great Sea — and one of them involves your boat! After clearing out the fog, you can return to Toad Town to purchase an engine upgrade for your vessel. It’s only 5,000 coins and I highly recommend grabbing it. You can earn tons of cash in the Great Sea by completing a combat trial in the lower-left corner of the map. You can also find tons of treasure by chatting with toads, or saving Hidden Toads on each island.

Below, I’ll explain how to reach Diamond Island, and map out all the other islands on the map.

Paper Mario: The Origami King – Table Of Contents:

Green Streamer Region: Pt. 21: Visit All 5 Hot Springs | Shangri-Spa | Pt. 22: Cutting The Green Streamer | Bowser’s Castle

Peach’s Castle: Pt. 23: Defeat Ollie | Final Dungeon

The Great Sea Walkthrough

Back at the Great Sea, keep going north and you’ll spot the streamer as it emerges from the deep blue sea. The big problem is all the fog on the edge of the map.

Go into the fog, and your Ship Captain will tell tales of Captain Ode. Hey, we’ve met that guy! And we know where his ship, the Marino, is kept on display.

Return to the Toad Town Museum (press [B] to automatically return to town) and talk to Captain Ode. He’ll trade you the Sea Chart you need to get through the fog — if you help him get his submarine into the water.

You don’t have to do anything. Mario’s pals get the job done. You’ll gain the [Sea Chart] after the cutscene. Now you can get back on the water and cut through the thick fog.

Quest: Solve The Mystery Of The Fog

Your first goal in The Great Sea is Bonehead Island. It’s the first spot marked on your map! Press [L] to find your way when you’re in thick fog. Let’s ignore the Purple Streamer for now and head to the skull marker on your sea map.

NOTE: Now that you have the Marino, you can dive at any time! Like Professor Toad, the Marino can search underwater anywhere. Press [Down] to dive for treasure.

On Bonehead Island, you can purchase a 10,000 Step Counter accessory to earn coins while you walk, and find a coffee shop door. It’s in a hidden alcove in the back-right of the island.

Hidden Toad: On the upper ledges to the left of the skull on Bonehead Isle, there’s a toad. Free him to get a buried treasure location marked on your map.

How To Unlock The Bonehead Door: Enter through the left hear of the Bonehead Island skull. To solve the first puzzle, hit the fireplaces so 1,2 & 4 are lit up. Then hit the button that appears to unlock the skull-shaped door.

Collectible Treasure: Submarine “Marino” — In the treasure chest in the second floor of the Bonehead Island skull.

At the top of the skull, exit the front door and slide down to enter the nose cavity. Hit the statue with your hammer and read the inscription — you need to find three “orbs” on Diamond Island to discover paradise. Sounds like a clue!

Activating the statue also summons a giant fan that clears out all the fog! That’ll help your exploration a whole lot. Next up, we’ll need to reach Diamond Island. Before we can do that, there’s one more location we need to find.

Quest: Find Sea Tower Island

There’s no clues to Diamond Island’s location, so let’s just follow the Purple Streamer. On the way, you’ll find Mushroom Island.

Continue to follow the Purple Streamer until it goes back underwater. Nearby, you’ll find Heart Island! Let’s follow the Purple Streamer to the end. At the end, you’ll find the Sea Tower in the upper-left corner of the Sea Map.

Sea Tower Island is located at [B1] on the Sea Map. At Sea Tower Island, you’ll find a door with three missing orbs and Warp Pipe 4. There’s nothing we can do here. The goal is to find three orbs on Diamond Island! So let’s start hunting.

Quest: Find Diamond Island

NOTE: Return to Toad Town to upgrade your ship engine for 5,000 coins. You’ll move twice as fast! Very helpful for exploring.

To find Diamond Island, we need to find clues scattered around The Great Sea. There are four islands you need to find — Heart Island, Spade Island, Club Island, and Crescent Moon Island. Let’s explore all four islands now.

Exploring Heart Island — Location: D4

This island is full of buttons. Your goal is to reach the [MAX HP] heart in the center. Before it will appear, you’ll need to hit the paper bushes and reveals buttons — hit the button on the center-right, and the front-ish left to make the heart spawn.

Now you need to reach the heart. Go behind the heart pillar to find a single bush. Hit this button to make a ramp appear. Next, hit the button at the front of the island to make the statue roll its ball down the ramp. Use it to climb up and hit the final button near the statue to create a bridge to the MAX HP heart.

Hidden Toad: Hit the heart at the top of Heart Island. It’s just a toad, but he’ll reward you with a [MAX HP UP] heart.
- MAX UP Heart +20

Hidden Toad: Found in the chest on Heart Island. Go through the small cave beneath the statue. This toad will mark another treasure location on your map.

Before leaving Heart Island, check on the strange statue at the top. It’ll give you a clue — who knows for what, but just remember it!

Heart Island Clue: Heart Symbol – Down

Exploring Spade Island — Location: D1

Welcome to tiny Spade Island! It’s a little place with a toad stuck in the center. You’ll need to find all the hidden toads to free him!

Hidden Toad: Inside an invisible block above the barrel to the left. Use confetti to fix the bottomless hole, then jump to the barrel and jump to hit a hidden block.

Hidden Toad: Hit the folding chair where the goomba is sitting. Hit the back part so it folds forward, revealing a hidden toad!
Hidden Toad: In one of the breakable barrels on the right edge of the island.
Hidden Toad: The last one is in the second coconut tree. Hammer it until this toad appears.
Hidden Toad: Push in all four toads, and the final toad will be freed. He’ll give you a secret fishing spot on your map.

There’s a statue on Spade Island too. Let’s take note of the clue.

Spade Island Clue: Spade – Up

Exploring Club Island — Location: B3

Smack the Hidden Toad right away, because he wants to reach the statue at the end of the island. To complete this island’s side-quest, you need to find all three Hidden Toads and lead them back to the seating area.

Hidden Toad: Found right at the start. You can’t miss him!

Hidden Toad: Three more are hidden in the tall grass. Activate the Toad Radar — if you need more battery, hit the trees behind the folding chairs to make a Snifit appear. He’ll recharge your batteries for 1,000 coins. Find all four toads to get a secret treasure location on your map.

You can skip the side-quest and just examine the statue to get your clue.

Club Island Clue: Club – Left

Exploring Crescent Moon Island — Location: F3

On this strange island, go to the dock at the back and catch the crab enemy. Once you pull it out, you’ll fight a Wave Battle. Clearing the battle generates an Earth Vellumental Magic Circle.

The [Diamond Key] chest was once located on this island — check the chest after raising the middle of the island. Luigi has been here already! He’s at Mushroom Island. You can access Mushroom Island now that you have the [Mushroom Handle]. The chest here has your final clue.

Crescent Moon Island Clue: Diamond – Center / Circle – Right

Exploring Mushroom Island — Location: E4

Once you have the [Mushroom Handle] from Crescent Moon Island, you can revisit Mushroom Island. Hit the left tree with your hammer to reveal a Fire Magic Circle. Use it to melt the ice and unlock the little house.

Hidden Toad: Find one flopping around as an origami fish on Mushroom Island.

In the backyard of Mushroom Island, you’ll find Luigi! Your lazy brother will hand over the [Diamond Key]. Take your new key down into the basement of Mushroom Island. You’ll discover something incredible — this is Olivia and Oliver’s birthplace!

There’s a mysterious figure trapped in this room. To save them, go to the left bookshelves and slam Luigi with your hammer to squish him. Jump on squished Luigi to launch up onto the bookshelf. Tear off the sticker and read this extremely mysterious book. You’ll learn about the Fold of Life…

Reading the book will generate a Magic Circle. Use it to free the Origami Craftsman and discuss what you know so far. This all leads you to our final objective — we’re FINALLY going to find Diamond Island.

Quest: How To Find The Diamond Island

If you’ve searched the Great Sea carefully, you’ll realize that Diamond Island is nowhere to be found. It’s actually hidden — and you’ve got a clue! After checking the statues on four islands (Club, Spade, Heart, Crescent) you’ll see that the Diamond is in the center.

To find Diamond Island, go to the center of the four islands and dive. Diamond Island is located at [D3]. Dive down with your submarine, and you’ll be able to access the area with the [Diamond Key].

Use the [Diamond Key] acquired from Luigi, and you’ll emerge in a massive underwater island. You’ll find all three orbs required to unlock the Sea Tower — each one is located in a different trial chamber. You can complete the trials in any order. We’ll tackle those trials next time.