Lagoona Trenches are where underwater mining takes place. Located at the bottom of Lagoona Lake, this place is only accessible from the Underwater Mining Vessel in Lagoona Research Lab. Players can find a vast and varied amount of items hidden deep within undersea rocks. These treasures consist of fossils, Evolutionary Stones, and other rare commodities, such as Heart Scales, Rare Bones and Odd Keystones.

Underwater Mining Vessel

The Underwater Mining Vessel is a small, yellow submarine that the player must operate in order to access the Lagoona Trenches. Talk to the blonde female scientist in the centre of Lagoona Lab and use an UMV Battery in order to activate the UMV and dive underwater. The first time player arrives in Lagoona Lab, the blonde scientist will offer the player a free UMV Battery. When underwater, the right bar indicates the battery status of UMV Submarine. Driving around and mining causes the battery to deplete, and when the bar is empty, the player surfaces and is sent back to the Lagoona Lab. If the player has run out of batteries, he or she will either have to win UMV Batteries from Hobo's Lucky Lotto as a prize, or buy more with Robux from the same blonde scientist in the following packs:

Batteries Selling Price (Robux) Price per battery Discount
1 5 5 None
3 11 Approximately 3.67 Appr. 27% off
6 18 3 40% off

Note: The player is required to save before mining. This is to prevent players from using the free battery from trying again and again to get the items they want. If the game unfortunately crashes or is suddenly disconnected, the player cannot try again.

Mining

The mining process is nearly identical to Sinnoh Underground in the core series games Pokémon Diamond, Pearl and Platinum, only with hammer switched for dynamites, and the pick changed to a drill. Find and click on sparkling parts of the wall to start mining. Like in real games, if the wall sustains too much damage before treasures are all dug out, it will collapse, destroying all treasures that are not retrieved in time. There is a green bar on the top to show how much damage the wall has sustained, and the player must dig out as many items as possible before the bar fills up.

Each time the player digs, the number of items ranges between 1 to 4 inclusively. The treasures are also similar to those in Sinnoh Underground, meaning that Fossils, Shards, Plates, certain kinds of Evolutionary Stones and some rare items can be excavated, but with the following changes:

  • The 4 fossils found in Unova and Kalos are also added.
  • All kinds of spheres are removed.
  • The Pixie Plate is added.
  • New Fossilized Eggs are added. They yield unique and rare Pokémon, including the Legendary Lake Guardians.

Treasures

Fossil Pokémon

Certain ancient Pokémon Fossils can be excavated within undersea rocks. Take these Fossils to the back of Lagoona Lab, and talk to the male scientist near the Fossil Revival machine to reap the benefits of player's spoils. They are automatically set to Lv. 10 upon revival. These fossils can also be traded to other Pokémon trainers when given to a Pokémon to hold.

Fossil Pokémon / Type Image Evolving Level Evolved Form / Type Image
Kanto Fossil Pokémon
Helix Fossil Mining.png
Helix Fossil
Omanyte
Rock
Water
Omanyte XY.gif Lv. 40 Omastar
Rock
Water
Omastar XY.gif
Dome Fossil Mining.png
Dome Fossil
Kabuto
Rock
Water
Kabuto XY.gif Kabutops
Rock
Water
Kabutops XY.gif
Old Amber Mining.png
Old Amber
Aerodactyl
Rock
Flying
Aerodactyl XY.gif N/A
Hoenn Fossil Pokémon
Root Fossil Mining.png
Root Fossil
Lileep
Rock
Grass
Lileep XY.gif Lv. 40 Cradily
Rock
Grass
Cradily XY.gif
Claw Fossil Mining.png
Claw Fossil
Anorith
Rock
Bug
Anorith XY.gif Armaldo
Rock
Bug
Armaldo XY.gif
Sinnoh Fossil Pokémon
Skull Fossil Mining.png
Skull Fossil
Cranidos
Rock
Cranidos XY.gif Lv. 30 Rampardos
Rock
Rampardos XY.gif
Armour Fossil Mining.png
Armour Fossil
Shieldon
Rock
Steel
Shieldon XY.gif Bastiodon
Rock
Steel
Bastiodon XY.gif
Unova Fossil Pokémon
Cover Fossil DW.png
Cover Fossil
Tirtouga
Water
Rock
Tirtouga XY.gif Lv. 37 Carracosta
Water
Rock
Carracosta XY.gif
Plume Fossil DW.png
Plume Fossil
Archen
Rock
Flying
Archen XY.gif Archeops
Rock
Flying
Archeops XY.gif
Kalos Fossil Pokémon
Jaw Fossil DW.png
Jaw Fossil
Tyrunt
Rock
Dragon
Tyrunt XY.gif Lv. 39
Daytime Only
Tyrantrum
Rock
Dragon
Tyrantrum XY.gif
Sail Fossil DW.png
Sail Fossil
Amaura
Rock
Ice
Amaura XY.gif Lv. 39
Overnight Only
Aurorus
Rock
Ice
Aurorus XY.gif

Fossilized Eggs

A Fossilized Egg being excavated.

Different from normal fossils, these Pokémon are hatched from revived Fossilized Eggs found in underwater mining. The Fossilized Eggs are unique to this game. They are stored in the player's party or PC instead of his or her bag. The resurrection process is similar to other fossils — the player must take the Fossilized Eggs to the back of Lagoona Lake Lab and talk to the male scientist for revival. Note that soft resetting does not alter the result. Obtained from Fossilized Eggs, the "Lake Guardians" Uxie, Mespirit and Azelf are the only Legendary Pokémon available in eggs.

The profile of a Fossilized Egg. It requires revival in the Research Lab before hatching.

Treasure Rate Egg Pokémon
Fossilized Egg.png
Fossilized Egg
85%
Togepi Egg.png
Togepi XY.gif
Togepi
Fairy
5%
Mesprit Egg.png
Mesprit XY.gif
Mesprit
Psychic
5%
Azelf Egg.png
Azelf XY.gif
Azelf
Psychic
5%
Uxie Egg.png
Uxie XY.gif
Uxie
Psychic

Evolutionary Stones

Also found underwater are various Evolutionary Stones that can be used on specific Pokémon to help them evolve. With the exception of Oval Stone, all stones listed below are directly used on Pokémon to trigger evolution.

Stone Image Compatible Pokémon
Fire Stone
Fire Stone Mining.png
Vulpix (Kanto Form)GrowlitheEeveePansear
Water Stone
Water Stone Mining.png
PoliwhirlShellderStaryuEeveeLombrePanpour
Thunder Stone
Thunder Stone Mining.png
PikachuEeveeEelektrik
Leaf Stone
Leaf Stone Mining.png
GloomWeepinbellExeggcuteNuzleafPansage
Sun Stone
Sun Stone Mining.png
GloomSunkernCottoneePetililHelioptile
Moon Stone
Moon Stone Mining.png
NidorinaNidorinoClefairyJigglypuffSkittyMunna
Oval Stone
Oval Stone Mining.png
Happiny

Other Treasures

There are a handful of other items that can be dug out via underwater mining. The rarity of these spoils varies.

Item Image Usage Rarity
Revive
Revive Mining.png
Restores a fainted Pokémon's health by half upon usage. Rare
Max Revive
Max Revive Mining.png
Completely restores a fainted Pokémon's health upon usage. Very Rare
Everstone
Everstone Mining.png
Prevents all kinds of evolution once held.
If held by either parent in Lagoona Day Care, holder's nature will be passed down to the bred Pokémon.
Uncommon
Plates Increase the damage of attacks from the corresponding type by 20% if held. Rare
Light Clay
Light Clay Mining.png
Extend the effect of Reflect, Light Screen and Aurora Veil by 3 more turns once held, if not broken by Brick Break or blown away by Defog. Uncommon
Star Piece
Star Piece Mining.png
Sell for 4900 dollars. Rare
Rare Bone
Rare Bone Mining.png
Sell for 5000 dollars. Rare
Shards N/A (Possible for paying Move Tutors later on) Common
Iron Ball
Iron Ball Mining.png
Reduces speed when held and, if the holder belongs to Flying-type or has the ability Levitate, eliminates immunity to Ground-type attacks. When thrown by the move Fling, this item causes the most damage. Uncommon
Heart Scale
Heart Scale Mining.png
Pay the Move Reminder in Colosseum Marketplace for remembering forgotten moves. Very Rare
Hard Stone
Hard Stone Mining.png
Increases the damage of Rock-type attacks by 20% when held. Common
Heat / Damp / Icy / Smooth Rock Extend the duration of corresponding weather moves and abilities by 3 more turns when held. For example, Heat Rock extends the effect of Sunny Day and ability Drought to 8 turns. Rare
Odd Keystone
Odd Keystone Mining.png
Throw into the Old Well on Route 8 to summon the Pokémon Spiritomb. Very Rare

Trivia

  • As surprising as it may seem, Pokémon Eggs can actually be hatched underwater.
  • Some underwater treasures are very rare and have a very high value to other trainers, who might be willing to trade for them in Trade Resort.
  • The music in Lagoona Trenches is based on Through the Sea of Time from the side series game Pokémon Mystery Dungeon: Explorers of Time, Darkness & Sky. This remix theme is made by famous music remix creator GlitchxCity.
Roria
Roria.png
Towns Mitis TownCheshma TownLagoona Lake (Trenches) • Port Decca (Beach) • Crescent TownHaunted Badge
Cities Silvent CityArc BadgeBrimber CityBrimstone BadgeRosecove CityFloat Badge (Beach) • Anthian City (Housing Dist.Shopping Dist.Battle Dist.Soaring BadgeParkSewer) • Aredia CityCrater Badge (Old ArediaAredia Ruins) • Fluoruma CityHarvest BadgeFrostveil CityContrast Badge (Catacombs)
Routes 123456789101112131415161718
Caves &
Mountains
Glistening GrottoSteam ChamberMt. Igneus (Igneus Depths) • Path of TruthSilver CoveMt. Cragonos (MinesCliffsPeakSanctuarySpringChamber of the Jewel) • Desert CatacombsNature's DenCalcite ChamberMartensite ChamberDendrite ChamberTitans' ThrongFreezing FissureOcean's OriginAborille Outpost (Demon's Tomb)
Islands Crescent Island (TownAborille Outpost) • Lost Islands (Deep Jungle) • Voltridia Island (Cavern) • Frigidia Island (Cavern) • Obsidia Island (Cavern)
Other
Locations
Gale ForestOld GraveyardSecret GroveGrove of DreamsFortulose ManorCosmeos Valley (Observatory) • Tinbell Tower (Construction Site) • Secret LabSafari ZoneEclipse BaseGene Lab
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