Beneath the Waves (W5) is the late West underwater level that opens after you play the Red Music Box from The Stagnant Swamp. Use the finder below for every Gray, Red, Green, and Blue chest, the Explosive Plunger Box progression treasure, the Red Crayon golf piece, all eight Musical Coins, and exact room-map links for Day/Night and each map variant.
FIRST CLEAR PRIORITY
Open the Gray Chest for the Explosive Plunger Box
Carry the Gray Key to the Gray Chest and take the Explosive Plunger Box. It unlocks S5 Cave of Flames V3, E4 The Colossal Hole V4, and E1 The Stagnant Swamp V4 for later clean-up routes. Come back for the Red Crayon, Red Chemical, Clubs Crest, and Musical Coins as Prince Frog's Gloves, Sapling of Growth, or both chemicals open harder variants.
W5 CHECKLIST · BENEATH THE WAVES
Beneath the Waves Finder
0 / 12 targets marked · browser checklist only
Map links open the Room & Target Index for this level. Match Day/Night and variant to your overworld state. Bring Swimming Flippers before deep dives. Progress is stored only in this browser.
ALL FOUR CHESTS · W5
Beneath the Waves treasures by chest color
Each chest needs its matching key color in the same level. Colors are not unlocked globally—if you drop a key, go back and pick it up again. Room numbers below match the default Day layout. Open a map link to see live markers for your current Day/Night and variant.
| Chest | Treasure | Key rooms | Chest room | What it does | Map |
|---|---|---|---|---|---|
| Gray / Grey | Explosive Plunger Box |
2, 9 | 18, 24, 25, 26 | Unlocks Cave of Flames V3, Colossal Hole V4, and Stagnant Swamp V4. | Open Gray Chest map |
| Red |  Red Crayon |
20, 21 | 6 | One of seven crayons. Collect all seven to open the Golf Building. | Open Red Chest map |
| Green |  Red Chemical |
7 | 5 | With Blue Chemical (S4 Blue Chest), unlocks Beneath the Waves V4 and The Vast Plain V4. | Open Green Chest map |
| Blue |  Clubs Crest |
19 | 4 | Card-suit collectible with Spades, Hearts, and Diamonds Crests for full clear. | Open Blue Chest map |
PROGRESSION · EXPLOSIVE PLUNGER BOX
What the Explosive Plunger Box unlocks
The Gray Chest treasure is pure map-progress fuel. After you leave the level with it, three later layouts open for chest and coin clean-up:
| What you get | Where | What it unlocks next |
|---|---|---|
| Cave of Flames map variant 3 | S5 after Explosive Plunger Box | Extra revisit routes inside Cave of Flames |
| The Colossal Hole map variant 4 | E4 after Explosive Plunger Box | Late Colossal Hole layout for remaining targets |
| The Stagnant Swamp map variant 4 | E1 after Explosive Plunger Box | Late swamp layout after you already opened W5 from here |
GOLF · RED CRAYON
Red Crayon and the Golf Building
The Red Chest holds the Red Crayon, one of seven crayons scattered across the game. Collecting every crayon colors the Golf Building on the North–West overworld border and opens its four fixed courses. Golf doors inside levels can still be used without the full set; the Building is the full side-mode hub.
How to unlock Golf (crayons checklist) → · Red Chest room map →
MUSICAL COINS · MUSIC COINS
All 8 Musical Coins in Beneath the Waves
Every level has eight Musical Coins. They are not required for the Perfect treasure screen, but finishing all 200 coins across the game unlocks Golf Building Course 4. Room numbers below match the default Day layout.
| Coin | Primary rooms | Also present in |
|---|---|---|
| Musical Coin 1 | 2 | 7 |
| Musical Coin 2 | 4 | — |
| Musical Coin 3 | 9 | — |
| Musical Coin 4 | 17 | 22, 23 |
| Musical Coin 5 | 18 | 24, 25, 26 |
| Musical Coin 6 | 19 | — |
| Musical Coin 7 | 20 | 21 |
| Musical Coin 8 | 20 | 21 |
Open all Musical Coin markers on the Room & Target Index → · Full Musical Coins Finder for every level →
UNLOCK · OVERWORLD
How to open Beneath the Waves
Red Music Box opens the West water path
Collect the Red Music Box from the Green Chest in E1 The Stagnant Swamp, then play it on the overworld. That opens W5 Beneath the Waves from W3 The Pool of Rain.
Bring the Swimming Flippers (S3 Tower of Revival Gray Chest) so you can dive. Prince Frog's Gloves (N1 Out of the Woods Green Chest) open W5 map variant 2 and help against strong currents.
Stagnant Swamp Red Music Box → · Open Beneath the Waves map → · Music Boxes & day/night →
MAP VARIANTS · DAY & NIGHT
When Beneath the Waves layout changes
W5 has four progression variants on both Day and Night. Variant 1 is available as soon as the Red Music Box opens the level. Later variants open after you collect specific treasures elsewhere:
| Variant | Requirements | Notes | Map |
|---|---|---|---|
| V1 | None (Red Music Box already played) | Default visit. Grab Explosive Plunger Box, Red Crayon, Red Chemical, and Clubs Crest routes here when open. | Open Day map |
| V2 | Prince Frog's Gloves (N1 Out of the Woods Green Chest) | Current-swimming upgrade and extra W5 revisit routes. | Open Day map |
| V3 | Sapling of Growth (W4 A Town in Chaos Blue Chest) | Later West layout for remaining underwater paths. | Open Day map |
| V4 | Blue Chemical (S4) + Red Chemical (W5 Green Chest) | Late-game layout after both chemicals. Also opens The Vast Plain V4. | Open Day map |
VISIT ROUTE
What to do in Beneath the Waves when it first opens
Gray Key → Plunger Box
Hunt the Gray Key in rooms 2 or 9, carry it to the Gray Chest in rooms 18 / 24–26, leave the level, and confirm Cave of Flames V3 or Colossal Hole V4 if you need those routes next.
Crayon + Chemical
Grab Red Crayon for Golf progress and Red Chemical for the chemical pair. Mark Clubs Crest and any open Musical Coins on the same loop when the path is free.
Revisit on V2–V4
Return with Prince Frog's Gloves, Sapling of Growth, or both chemicals for sealed underwater rooms and the last Musical Coins.
FAQ
Beneath the Waves FAQ
How do you open Beneath the Waves in Wario Land 3?
Collect the Red Music Box from the Green Chest in E1 The Stagnant Swamp, then play it on the overworld. The new path opens from W3 The Pool of Rain into W5 Beneath the Waves.
What treasure is in the Gray Chest?
The Explosive Plunger Box. On the default Day map the Gray Key is in rooms 2 and 9, and the Gray Chest is in rooms 18, 24, 25, and 26. It unlocks Cave of Flames V3, Colossal Hole V4, and Stagnant Swamp V4.
Where is the Red Crayon?
Open the Red Chest in Beneath the Waves. Key rooms are 20 and 21; the chest is in room 6. It is one of the seven crayons needed for the Golf Building.
What does the Red Chemical do?
Paired with Blue Chemical from The Steep Canyon Blue Chest, it unlocks Beneath the Waves map variant 4 and The Vast Plain map variant 4. Grab it on W5 even if Blue Chemical comes later.
Do I need Swimming Flippers?
Yes for deep water. Get the Swimming Flippers from the Gray Chest in S3 Tower of Revival. Prince Frog's Gloves improve current swimming and unlock W5 variant 2.
How many Musical Coins are in Beneath the Waves?
Eight—the same as every other level. Use the coin table above or the full Musical Coins Finder if you are missing one for 100% side goals.
Does Beneath the Waves have a boss?
No named boss arena is tied to Beneath the Waves. The level's main value is the Explosive Plunger Box map variants, the Red Crayon for Golf, and the Red Chemical pair.
Is it Gray Chest or Grey Chest?
Both spellings refer to the same chest. This guide uses Gray in player-facing text and also matches grey in search.