Diving in Coral Island: How to Unlock the Merfolk Kingdom & All Sea Critters

There’s a whole new world to explore underwater. Here’s everything you need to know about Diving in Coral Island.

Diving in Coral Island

Screenshot by Gamepur

Coral Island includes every feature you’d expect from a farming sim game while remembering its Indonesian roots with its novel diving mechanic. We know the basics of fishing, farming, and mining all too well, but what is this new activity all about?

You suit up in an adorable diving ensemble, team up with a cute robo-buddy, and dive into the underwater world to heal corals. The goal is simple: clear the trash so corals can breathe again. However, that doesn’t mean you must clear every piece of trash in the area. And, as you explore, you might stumble upon some precious forageables, encounter critters, and even uncover a hidden civilization. This guide covers everything you need to know about diving in Coral Island.

How Diving Works in Coral Island: Tips & Tricks

How Diving Works in Coral Island
Screenshot by Gamepur

Diving is pretty similar to mining. If you’ve played other farming sims, you’ll notice that trash can be collected like rocks can be broken. Instead of a pickaxe, you’ll use the scythe to remove trash from the ocean floor.

The goal is not to clear the entire area, though I’m sure that would make everyone feel better. Still, losing track of the objective will deplete your entire stamina bar.

To progress through the underwater map, you must uncover solar orbs, tiny, golden devices hidden underneath the trash. This technology will power up a solar pillar that will heal coral sites when it finds the right place. So, to heal a coral site on Coral Island, follow these steps:

  1. Clear trash near a contaminated (black) coral site until a tiny solar orb emerges.
  2. Activate the solar orb to power up the pillar nearby.
  3. Remove the trash marked with red to unblock the solar energy’s path.
  4. Wait for a little cinematic, and the coral site will be healed.

Every now and then, a sea turtle or seal will be freed from a root prison when the solar pillar is activated. Interact with them to receive a stamina-replenishing snack.

How to Use Kelp in Coral Island

While diving in Coral Island’s underwater map, you’ll start to amass quite the Kelp collection. In the early game, I would rush back home and drop all my kelp in the shipping bin, hoping to get a bit of gold.

Don’t be like me.

Use kelp to upgrade seeds, plants, and fruit trees in the lab. Kelp can be turned into Kelp Essence with the Extractor, a machine you can craft. With upgraded seeds, the quality of your produce will improve, and you’ll make way more money than just by selling regular kelp.

How to Unlock the Merfolk Kingdom & Enter Underwater Caves in Coral Island

Coral Island Unlock Underwater Cave
Screenshot by Gamepur

As you progress through the underwater map, you’ll spot some caves with closed gates, like the Se Pulu and Dua Pulu caves. 

You’ll first need to unlock the Merfolk Kingdom to enter underwater caves. When you do, a character named Cho Oyu will give you access to the caves. 

Related: Romance in Coral Island: All Romance Candidates, Marriage & Children

I unlocked the Merfolk Kingdom in Coral Island by following the retreated root and opening the root-infested gate in Dua Pulu. This is all part of a main quest, so you should stick to the Heal the Ocean quest to get there.

How to Follow the Retreated Root & Find a Way to Open the Gate in Coral Island

Coral Island Open Gates Diving
Screenshot by Gamepur

After cleaning your first 20 coral sites, all of Se Pulu will be cleansed of the root. This will trigger a cutscene where you’ll meet some of the Merfolk. Though they’ll flee the scene, you can catch up with them by following the retreated root. However, this is easier said than done since the path is often blocked.

To follow the retreated root in Coral Island, I cleaned coral sites along the way. Usually, after cleaning one or two, the root barrier blocking the way would disappear.

Eventually, the root took over a gate, and the quest objective became quite vague: “Find a way to open the gate.” To open the gate to the Merfolk Kingdom in Coral Island, I healed all 20 Dua Pulu coral sites. This instantly caused the root to retreat further back, leaving the entrance to the Merfolk Kingdom open.

All Sea Critters in Coral Island & Where to Find Them

Screenshot by Gamepur
AppearanceSea Critter NameSeasonTimeLocation
Arrow CrabSpring and WinterEvening and Night10m
Common StarfishAnyAny10m
Tigertail SeahorseSpring, Fall, and WinterEvening and Night10m
Blue LobsterFall and WinterEvening and Night10m
Mauve Stinger JellyfishSummer and FallEvening and Night10m
Cannonball JellyfishSpring, Summer, and FallAny10m
Upside-down JellyfishAnyMorning and Afternoon10m
Pom-pom CrabSpring and SummerAny10m
Sea SlugAnyAny10m
Venus’s Flower BasketSpring, Fall, and WinterAny10m
Yeti CrabSpring and SummerEvening and Night10m
Flowerhat JellyfishSpring, Summer, and WinterEvening and Night20m
Jayakar’s SeahorseSpring and FallAny20m
Skunk Cleaner ShrimpAnyAny20m
Eight-armed Sea StarAnyMorning and Afternoon20m
Mantis ShrimpSpring and WinterAny20m
Hermit CrabAnyAny20m
White-spotted JellyfishFall and WinterEvening and Night20m
Calico LobsterSummer, Fall, and WinterEvening and Night20m
Brisingida StarfishFall and WinterAny20m
Ruby SeadragonSummer, WinterMorning and Afternoon20m
Giraffe SeahorseAnyAny40m
Atolla JellyfishSpring, Summer, and FallAny40m
Cauliflower JellyfishSummer and FallAny40m
Horseshoe CrabSpring and SummerEvening and Night40m
Blue CrabSpring, Summer, and FallEvening and Night40m
Sexy ShrimpAnyMorning and Afternoon40m
Split-colored LobsterSpring and WinterEvening and Night40m
Crown-of-thorns StarfishSpring, Summer, and WinterAny40m
Hedgehog SeahorseAnyAny40m
Chambered NautilusSpringMorning and Afternoon40m
Fuchsia FlatwormSummer, Fall, and WinterMorning and Afternoon40m
Bloodbelly Comb JellyfishAnyAny50m
Pink Meanie JellyfishWinterAny50m
Harlequin ShrimpSummer and WinterEvening and Night50m
Cotton Candy LobsterFallEvening and Night50m
Sunflower Sea StarSea Star SummerAny50m
Red Knob StarfishSummer and WinterAny50m
Blue StarfishSpring, Summer, and FallEvening and Night50m
Leafy SeadragonFallMorning and Afternoon50m
Shiho’s SeahorseFall and WinterAny50m
Sea AnemoneAnyAny50m
Giant IsopodSummer and FallMorning and Afternoon50m
Stone CrabSpring, Fall, and WinterEvening and Night50m

All Ocean Scavengeables in Coral Island & Where to Find Them

Screenshot by Gamepur
AppearanceOcean ScavengeableLocation
Black Sea Urchin10-20m
Blood Clam10-20m
Duck Mussel10-20m
Giant Clam10-20m
Jackknife Clam10-20m
Mediterranean Scallop10-20m
Pacific Oyster10-20m
Steamer Clam10-20m
Zebra Mussel20-30m
Amber Pen Shell20-30m
Belon Oyster20-30m
Blue Mussel20-30m
Calico Scallop20-30m
Cherrystone Clam20-30m
Eastern Oyster20-30m
Gooseneck Barnacle20-30m
Purple Urchin20-30m
Bay Scallop40-50m
Blue Oyster40-50m
Green-lipped Mussel40-50m
Green Sea Urchin40-50m
Kumamoto Oyster40-50m
Patagonian Scallop40-50m
Razor Clam40-50m
Sea Lettuce40-50m
Heart Urchin50-60m
Horse Mussel50-60m
King Scallop50-60m
Olympia Oyster50-60m
Queen Scallop50-60m
Red Sea Urchin50-60m
Sea Grapes50-60m
Sea MushroomAny
Sea SaltAny