Operation Deep-Dive Treasure
Last updated 2026-09-11
Operation Deep-Dive Treasure is a part of the Sunny Summer Fontinalia event.
It is unlocked by completing the Event World Quest Elegance? Safety First! in Sunny Summer Fontinalia (Event) and accessed by interacting with the door with the
icon aboard the Wingalet.
Tutorial
Rules


Do note that certain powerful creatures marked with a special icon are capable of dealing more damage, so be extra careful when you're dealing with them!

Any nearby items available for pickup will also be displayed on the left side of the Treasure Inventory interface.
Arrange items and rotate them as necessary to maximize the available space in your inventory.


You have a chance of finding high-value items with every container type. The more containers you find, the higher the chance that you surface with a veritable haul...

You may carry up to one consumable item at any one time, which cannot be brought out with you when you surface.

Certain rendezvous points will only work after the corresponding mechanisms have been activated.

You can expand the space available in the Safety Capsule through "Marvelous Abilities."


Combat Abilities


Hold down on the Skill button to expand the shield, and release to unleash the shockwave in the targeted direction. If you're attacked during this time, an even more powerful energy projectile will be unleashed.
Other Tips



Water Zones
I: Silent Sea Valley
- Water Zone Information
| Map | Description |
|---|---|
|
A long and narrow underwater valley beneath what was once an important sailing route to the Fontaine Research Institute, a route that has been out of use for years. Many Hunter's Rays dwell in this area. Be careful not to get surrounded by them, as that would put you at a serious disadvantage. |
- Possible Enemies
- Possible Collectibles
- Nemesis
- Special Challenge
- Special: Find Seelie and remove the seal
- Find the 2 Seelie(0/2)
II: Court Ruins
- Unlock condition
- Complete the Management Commission "VI. Business Benchmark III"
- Water Zone Information
| Map | Description |
|---|---|
|
A body of water located southwest of the Court of Fontaine. The bottom is dotted with the ruins of an ancient city, one of which still contains many lost treasures. As the pollution grows, the long-hidden "Self-Proclaimed Lord of Scrapland" is now active in this area again... |
- Possible Enemies
- Possible Collectibles
- Nemesis
- Special Challenge
- Special: Defeat the guards and enter the building
- Defeat the opponents(0/2)
- Defeat the opponents(0/3)
III: Unfortunate Plain
- Unlock condition
- Complete the Management Commission "X. Business Benchmark IV"
- Water Zone Information
| Map | Description |
|---|---|
|
An underwater plain teeming with various aquatic plants. Located between the Court of Fontaine and Lumidouce Harbor, the area once saw numerous incidents due to heavy ship traffic. Today, many underwater automatic cannons here are still active... |
- Possible Enemies
- Possible Collectibles
- Nemesis
- Special Challenge
- Special: Turn Off cannons and activate mechanism
- Turn off the 2 cannons(0/2)
- Locate the missing crystal "receiver nodes" of the ship's cannons to gain control over the cannons
- Use the ability of the Xenochromatic Ball Octopus on the crystal receiver node to gain control over the naval cannon(s)
- Successfully override and take control of the Autocannon
- [Optional] Fire a powerful Hydro bullet in the direction the cannon is aimed!
- Activate the mechanism(0/1)
- Activate the Special Rendezvous Point Toggle in the nearby glass building
- Turn off the 2 cannons(0/2)
IV: Fortress Perimeter
- Unlock condition
- Complete the Management Commission "XIV. Business Benchmark V"
- Water Zone Information
| Map | Description |
|---|---|
|
A key body of water above the Fortress of Meropide. High levels of pollution have led to the proliferation of Hat Jellyfish in this area. Take care not to be locked on by the searchlights — you might be mistaken for a dangerous creature and run into quite a bit of trouble... |
- Possible Enemies
- Possible Collectibles
- Nemesis
- Special Challenge
- Special: Turn off the searchlights while staying out of the light
- Turn off the 3 searchlights(0/3)
V: The Dangerous Deep
- Unlock condition
- Complete the Management Commission "XIV. Business Benchmark V"
- Water Zone Information
| Map | Description |
|---|---|
|
This body of water is home to a key sailing route between the Beryl and Belleau Regions, as well as the highly dangerous Elton Trench below. Many rumors of the Grand Fleet are said to be buried here, along with a giant Blubberbeast that has been missing for years... |
- Possible Enemies
- Possible Collectibles
- Nemesis
- Special Challenge
- Special: Track the phantom
- Follow the phantom to the target location(0/1)
Side Commissions
Unlocked after completing the Management Commission "I. Debut"
Side Commissions are grouped into sets of similar tasks. Some will only become available after completing previous tasks in the set.
Collect Items
Unlocked after completing the Management Commission "VII. A New Home for the Recovering"[verification needed]
| Name | Objective | Commission Requirements | Operation Target | Commission Reward |
|---|---|---|---|---|
| Submit 1 piano bench (0/1) | Freminet seems to have something to tell us...
After completing the Event World Quest Something's Wrong With the Water in Sunny Summer Fontinalia (Event): "Looks like there are some valuable and unusual lost items underwater. Some of them might even have owners waiting to claim them..." |
|||
| Assemble 2 piano parts in the scene (0/2) | Assemble 2 piano parts in the scene
"We found some things that look like the makings of an instrument. Let's put them together first, then ask Freminet what he thinks." |
— | ||
| Submit 1 piano soundboard (0/1) | Freminet seems to have something to tell us...
After completing the Event World Quest The Underwater Salvage Commandments in Sunny Summer Fontinalia (Event): "We've salvaged quite a few parts by now. At this rate, it's only a matter of time before we have enough to assemble a complete piano. Let's go tell Freminet the good news!" |
|||
| Assemble 5 piano parts in the scene (0/5) | Assemble 5 piano parts in the scene
"We've found all the parts of the mechanical piano. Now let's put it together and see..." After completing the commission: |
— |
Water Zone I: "Silent Sea Valley"
| Name | Objective | Commission Requirements | Commission Reward |
|---|---|---|---|
| Quelling the Restless: Sea Valley I | Bring out 5 green-grade dangerous creatures in total (0/5) | Bring out 5 green-grade dangerous creatures from the Silent Sea Valley
"Aside from the largest and most unusual Fontemer Aberrants, we need to keep an eye on the other restless ones, too. The more we bring back to the aquarium, the safer these waters will become!" |
|
| Quelling the Restless: Sea Valley II | Bring out 5 blue-grade dangerous creatures in total (0/5) | Bring out 5 blue-grade dangerous creatures from the Silent Sea Valley
"Dangerous aquatic creatures are still roaming these waters. If they surround the divers, we'll be in trouble! The fewer of them there are out there, the easier it will be to get the situation under control. Let's keep at it!" |
|
| Hidden Hazard Survey: Sea Valley I | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in the Silent Sea Valley (You can find the corresponding location on the map)
"Ever since the waters became contaminated, conditions in some areas have changed completely. We should go take a look..." |
|
| Hidden Hazard Survey: Sea Valley II | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in the Silent Sea Valley (You can find the corresponding location on the map)
"Some divers have posted a commission asking someone with stronger combat skills to help investigate a designated area..." |
|
| Hidden Hazard Survey: Sea Valley III | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in the Silent Sea Valley (You can find the corresponding location on the map)
"Experts from the Fishing Association have noticed that the fish seem to be thinning out in some areas. We should go underwater and check what's going on..." |
|
| Treasure Hunt: Sea Valley I | Open 3 containers in total (0/3) | Open 3 containers in the Silent Sea Valley
"Come to think of it, there could be something good hidden in any chest underwater, right? Let's keep looking around. We might just find a surprise." |
|
| Treasure Hunt: Sea Valley II | Open 5 containers in total (0/5) | Open 5 containers in the Silent Sea Valley
"We've found some pretty nice things in those treasure chests already... Let's keep opening underwater containers. Sooner or later, we're sure to find some incredible treasure!" |
Water Zone II: "Court Ruins"
| Name | Objective | Commission Requirements | Operation Target | Commission Reward |
|---|---|---|---|---|
| Quelling the Restless: Ruins I | Bring out 5 green-grade dangerous creatures in total (0/5) | Bring out 5 green-grade dangerous creatures from the Court Ruins
"Aside from the largest and most unusual Fontemer Aberrants, we need to keep an eye on the other restless ones, too. The more we bring back to the aquarium, the safer these waters will become!" |
— | |
| Quelling the Restless: Ruins II | Bring out 5 blue-grade dangerous creatures in total (0/5) | Bring out 5 blue-grade dangerous creatures from the Court Ruins
"Dangerous aquatic creatures are still roaming these waters. If they surround the divers, we'll be in trouble! The fewer of them there are out there, the easier it will be to get the situation under control. Let's keep at it!" |
— | |
| Quelling the Restless: Ruins III | Bring out 2 Sternshield Crabs in total (0/2) | Bring out 2 Sternshield Crabs from the Court Ruins
"The Maison Gardiennage's meks have detected some targets that need special attention. Since we're headed that way anyway, let's round up these troublemakers and bring them back to the aquarium for some quiet recuperation." |
||
| Quelling the Restless: Ruins IV | Bring out 1 Underwater Survey Mek (Ousia) in total (0/1) | Bring out 1 Underwater Survey Mek (Ousia) from the Court Ruins
"A few combat divers were beaten into a panicked retreat... Looks like they ran into some malfunctioning meks. Who knew underwater pollution could have this kind of effect... We'll have to remove those meks, too!" |
||
| Hidden Hazard Survey: Ruins I | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in the Court Ruins (You can find the corresponding location on the map)
"Experts from the Fishing Association have noticed that the fish seem to be thinning out in some areas. We should go underwater and check what's going on..." |
— | |
| Hidden Hazard Survey: Ruins II | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in the Court Ruins (You can find the corresponding location on the map)
"Ever since the waters became contaminated, conditions in some areas have changed completely. We should go take a look..." |
— | |
| Hidden Hazard Survey: Ruins III | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in the Court Ruins (You can find the corresponding location on the map)
"Some divers have posted a commission asking someone with stronger combat skills to help investigate a designated area..." |
— | |
| Treasure Hunt: Ruins I | Open 3 containers in total (0/3) | Open 3 containers in the Court Ruins
"Come to think of it, there could be something good hidden in any chest underwater, right? Let's keep looking around. We might just find a surprise." |
— | |
| Treasure Hunt: Ruins II | Open 5 containers in total (0/5) | Open 5 containers in the Court Ruins
"We've found some pretty nice things in those treasure chests already... Let's keep opening underwater containers. Sooner or later, we're sure to find some incredible treasure!" |
— |
Water Zone III: "Unfortunate Plain"
| Name | Objective | Commission Requirements | Operation Target | Commission Reward |
|---|---|---|---|---|
| Quelling the Restless: Plain I | Bring out 3 Rosy Pink Angelic Sea Hares in total (0/3) | Bring out 3 Rosy Pink Angelic Sea Hares from the Unfortunate Plain
"Aside from the largest and most unusual Fontemer Aberrants, we need to keep an eye on the other restless ones, too. The more we bring back to the aquarium, the safer these waters will become!" |
||
| Quelling the Restless: Plain II | Bring out 3 Chocolate Brown Ball Octopuses in total (0/3) | Bring out 3 Chocolate Brown Ball Octopuses from the Unfortunate Plain
"Dangerous aquatic creatures are still roaming these waters. If they surround the divers, we'll be in trouble! The fewer of them there are out there, the easier it will be to get the situation under control. Let's keep at it!" |
||
| Quelling the Restless: Plain III | Bring out 2 Bubbler Seahorses in total (0/2) | Bring out 2 Bubbler Seahorses from the Unfortunate Plain
"The Maison Gardiennage's meks have detected some targets that need special attention. Since we're headed that way anyway, let's round up these troublemakers and bring them back to the aquarium for some quiet recuperation." |
||
| Quelling the Restless: Plain IV | Bring out 1 Underwater Patrol Mek (Pneuma) in total (0/1) | Bring out 1 Underwater Patrol Mek (Pneuma) from the Unfortunate Plain
"A few combat divers were beaten into a panicked retreat... Looks like they ran into some malfunctioning meks. Who knew underwater pollution could have this kind of effect... We'll have to remove those meks, too!" |
||
| Hidden Hazard Survey: Plain I | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in the Unfortunate Plain (You can find the corresponding location on the map)
"Some divers have posted a commission asking someone with stronger combat skills to help investigate a designated area..." |
— | |
| Hidden Hazard Survey: Plain II | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in the Unfortunate Plain (You can find the corresponding location on the map)
"Experts from the Fishing Association have noticed that the fish seem to be thinning out in some areas. We should go underwater and check what's going on..." |
— | |
| Hidden Hazard Survey: Plain III | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in the Unfortunate Plain (You can find the corresponding location on the map)
"Ever since the waters became contaminated, conditions in some areas have changed completely. We should go take a look..." |
— | |
| Treasure Hunt: Plain I | Open 3 containers in total (0/3) | Open 3 containers in the Unfortunate Plain
"Come to think of it, there could be something good hidden in any chest underwater, right? Let's keep looking around. We might just find a surprise." |
— | |
| Treasure Hunt: Plain II | Open 5 containers in total (0/5) | Open 5 containers in the Unfortunate Plain
"We've found some pretty nice things in those treasure chests already... Let's keep opening underwater containers. Sooner or later, we're sure to find some incredible treasure!" |
— |
Water Zone IV: "Fortress Perimeter"
| Name | Objective | Commission Requirements | Operation Target | Commission Reward |
|---|---|---|---|---|
| Quelling the Restless: Fortress I | Bring out 5 blue-grade dangerous creatures in total (0/5) | Bring out 5 blue-grade dangerous creatures from the Fortress Perimeter
"Aside from the largest and most unusual Fontemer Aberrants, we need to keep an eye on the other restless ones, too. The more we bring back to the aquarium, the safer these waters will become!" |
— | |
| Quelling the Restless: Fortress II | Bring out 1 Cherubic Sea Hare in total (0/1) | Bring out 1 Cherubic Sea Hare from the Fortress Perimeter
"Dangerous aquatic creatures are still roaming these waters. If they surround the divers, we'll be in trouble! The fewer of them there are out there, the easier it will be to get the situation under control. Let's keep at it!" |
||
| Quelling the Restless: Fortress III | Bring out 1 Clear Gold Hat Jellyfish in total (0/1)
Bring out 1 Sapphire Blue Hat Jellyfish in total (0/1) |
Bring out 1 Clear Gold Hat Jellyfish from the Fortress Perimeter
Bring out 1 Sapphire Blue Hat Jellyfish from the Fortress Perimeter "The Maison Gardiennage's meks have detected some targets that need special attention. Since we're headed that way anyway, let's round up these troublemakers and bring them back to the aquarium for some quiet recuperation." |
||
| Quelling the Restless: Fortress IV | Bring out 1 Underwater Patrol Mek (Ousia) in total (0/1) | Bring out 1 Underwater Patrol Mek (Ousia) from the Fortress Perimeter
"A few combat divers were beaten into a panicked retreat... Looks like they ran into some malfunctioning meks. Who knew underwater pollution could have this kind of effect... We'll have to remove those meks, too!" |
||
| Hidden Hazard Survey: Fortress I | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in the Fortress Perimeter (You can find the corresponding location on the map)
"Experts from the Fishing Association have noticed that the fish seem to be thinning out in some areas. We should go underwater and check what's going on..." |
— | |
| Hidden Hazard Survey: Fortress II | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in the Fortress Perimeter (You can find the corresponding location on the map)
"Some divers have posted a commission asking someone with stronger combat skills to help investigate a designated area..." |
— | |
| Hidden Hazard Survey: Fortress III | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in the Fortress Perimeter (You can find the corresponding location on the map)
"Ever since the waters became contaminated, conditions in some areas have changed completely. We should go take a look..." |
— | |
| Treasure Hunt: Fortress I | Open 3 containers in total (0/3) | Open 3 containers in the Fortress Perimeter
"Come to think of it, there could be something good hidden in any chest underwater, right? Let's keep looking around. We might just find a surprise." |
— | |
| Treasure Hunt: Fortress II | Open 5 containers in total (0/5) | Open 5 containers in the Fortress Perimeter
"We've found some pretty nice things in those treasure chests already... Let's keep opening underwater containers. Sooner or later, we're sure to find some incredible treasure!" |
— |
Water Zone V: "The Dangerous Deep"
| Name | Objective | Commission Requirements | Operation Target | Commission Reward |
|---|---|---|---|---|
| Quelling the Restless: The Deep I | Bring out 5 blue-grade dangerous creatures in total (0/5) | Bring out 5 blue-grade dangerous creatures from The Dangerous Deep
"Aside from the largest and most unusual Fontemer Aberrants, we need to keep an eye on the other restless ones, too. The more we bring back to the aquarium, the safer these waters will become!" |
— | |
| Quelling the Restless: The Deep II | Bring out 2 Lake Blue Hunter's Rays from The Dangerous Deep (0/2) | Bring out 2 Lake Blue Hunter's Rays from The Dangerous Deep
"Dangerous aquatic creatures are still roaming these waters. If they surround the divers, we'll be in trouble! The fewer of them there are out there, the easier it will be to get the situation under control. Let's keep at it!" |
||
| Quelling the Restless: The Deep III | Bring out 2 Blubberbeasts in total (0/2) | Bring out 2 Blubberbeasts from The Dangerous Deep
"The Maison Gardiennage's meks have detected some targets that need special attention. Since we're headed that way anyway, let's round up these troublemakers and bring them back to the aquarium for some quiet recuperation." |
||
| Quelling the Restless: The Deep IV | Bring out 1 Underwater Survey Mek (Pneuma) in total (0/1) | Bring out 1 Underwater Survey Mek (Pneuma) from The Dangerous Deep
"A few combat divers were beaten into a panicked retreat... Looks like they ran into some malfunctioning meks. Who knew underwater pollution could have this kind of effect... We'll have to remove those meks, too!" |
||
| Hidden Hazard Survey: The Deep I | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in The Dangerous Deep (You can find the corresponding location on the map)
"Some divers have posted a commission asking someone with stronger combat skills to help investigate a designated area..." |
— | |
| Hidden Hazard Survey: The Deep II | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in The Dangerous Deep (You can find the corresponding location on the map)
"Ever since the waters became contaminated, conditions in some areas have changed completely. We should go take a look..." |
— | |
| Hidden Hazard Survey: The Deep III | Explore the designated zone(s) (You can find the corresponding location on the map) (0/1) | Explore the designated danger zone(s) in The Dangerous Deep (You can find the corresponding location on the map)
"Experts from the Fishing Association have noticed that the fish seem to be thinning out in some areas. We should go underwater and check what's going on..." |
— | |
| Treasure Hunt: The Deep I | Open 3 containers in total (0/3) | Open 3 containers in The Dangerous Deep
"Come to think of it, there could be something good hidden in any chest underwater, right? Let's keep looking around. We might just find a surprise." |
— | |
| Treasure Hunt: The Deep II | Open 5 containers in total (0/5) | Open 5 containers in The Dangerous Deep
"We've found some pretty nice things in those treasure chests already... Let's keep opening underwater containers. Sooner or later, we're sure to find some incredible treasure!" |
— |
Gameplay Features
General Water Zone Features
Certain gameplay mechanics and items can appear in most or all Water Zones. These are indicated by unique icons on the map.
- There are two possible starting locations in each Water Zone, one of which is randomly selected for each operation in that zone. In all zones except Zone IV, the Rendezvous Point closest to the player's starting location will be moved to the opposite side of the map.
Pollution Phase
The pollution phase begins 7 minutes after the player enters the Water Zone, or immediately if the player has completed the Management Commission XVIII. "Battle Line, Bubbled" and chooses to enter the Pollution Phase directly.
A 30-second warning is given before each stage of pollution starts.
- Early-Stage Pollution
- Lasts for 5 minutes.
- The following message will appear: "During the Pollution Phase, you will take continuous damage, reducing Durability, and dangerous enemies will appear"
- Clockwork meka-type Dangerous Creatures will appear.
- All other creatures have a chance to become their Rampaging variants.
- Nemeses and the enemies in the Water Zone II Special Challenge will always become their Rampaging variants.[verification needed]
- If a creature is in combat or has previously been aggravated when the Pollution Phase starts, they will not transform into their Rampaging variant.[verification needed]
- Base damage without upgrades to Contamination Resistance: 0.5 Durability every 5 seconds
- Late-Stage Pollution
- The following message will appear: "Pollution has intensified, causing damage to occur more frequently"
- Meka-type creatures have a chance to become their Rampaging variants.
- If a meka-type creature is in combat or has previously been aggravated when the Pollution Phase starts, they will not transform into their Rampaging variant.[verification needed]
- Base damage without upgrades to Contamination Resistance: 1 Durability every 5 seconds
Combat Abilities
- After submitting the Management Commission in which a Water Zone's boss (the non-Rampaging version) must be defeated and retrieved, players can select any of their combat abilities to be their default ability in that Water Zone.
- The corresponding Management Commissions are as follows:
- Zone I: V. "The Gunsmiths' Departure"
- Zone II: IX. "The Lord of Scrapland's End"
- Zone III: XII. "Thus Falls the Faux-Holy Sword"
- Zone IV: XV. "Grease Removal"
- Zone V: XVIII. "Battle Line, Bubbled"
- All combat abilities will be at their respective levels in Marvelous Abilities.
- The corresponding Management Commissions are as follows:
- In addition to the selected combat ability for each Water Zone, various Xenochromatic Creatures can be found while diving. These can be attacked to temporarily gain their ability.
- Xenochromatic Creatures will disappear for the current dive after they are attacked.
- Only one temporary ability can be held at a time. Obtaining a new ability will replace the current one.
- Temporary abilities have no time limit but a limited number of skill uses (amount differs by ability). Temporary abilities will be lost when all skill uses are exhausted. Auto-casts do not count as skill uses.
- Players can switch between a temporary ability and their default ability if the temporary ability has not yet been used up.
- Temporary abilities will always be one level higher than the player's current level for the corresponding ability, up to Lv. 7, one more than the maximum level for standard combat abilities.
- A temporary ability of the same type as the default ability can be obtained. It will be one level higher.
Durability
- Amount: 4 + level of Ironhide
- Durability can be restored by consuming Healing Potions.
- Invincibility for ~3 seconds after receiving damage from a Dangerous Creatures that was not nullified through use of the Armored Shield Marvelous Ability.
- After receiving damage from Dangerous Creatures and temporarily becoming invincible 8 times, a random backpack slot is lost for the current dive, regardless of how much Durability was healed or how much Durability was lost per hit.
- If a Collectible or Dangerous Creature was present in that slot, it will fall out.
- Taking Damage
- Damage taken from Dangerous Creatures depends on the grade (green, blue, purple, or gold) and status (normal or Rampaging) of the creature.[Verify values below]
- Certain powerful creatures (purple-grade, Rampaging, and Nemeses) are initially considered extra dangerous and will deal more damage. They are indicated by a red or yellow
icon.
- After Condition missing, a red "extra dangerous" rating will be demoted to yellow.[Different for different creatures? For different Zones? And is it based on your total Marvelous Ability level count?]
- After Condition missing, a yellow "extra dangerous" rating will be cleared.[Different for different creatures? For different Zones? And is it based on your total Marvelous Ability level count?]
Dangerous Creature Durability Loss by Danger Level Grade Status Default Yellow Red Green Normal 0.5 1 1.5 Rampaging 1 ? 3 Blue Normal 0.5 1 1.5 Rampaging 1 2 3 Purple
(non-Meka)Normal 1 2 3 Rampaging 1.5 ? 4.5 Purple
(Meka)Normal 1.5 3 4.5 Rampaging 2 4 6 Gold
(only Nemeses)Normal, most Nemeses 1 2 3 Normal, Blubberbearer Recruit 0.5 1 1.5 Rampaging, most Nemeses 1.5 3 4.5 Rampaging, Blubberbearer Recruit 1 2 3
- Continuous damage taken during the Pollution Phase: See Pollution Phase
- Damage from underwater cannons: 1 Durability per hit
Consumables
Healing Potions can consumed to recover Durability. There is a chance to obtain one when searching a container, and only one can be carried at a time. If a Healing Potion is used while at maximum Durability, it will still be consumed.
Special Bait
Searching containers in Water Zones III–V will yield ![]()
Special Bait, with the amount varying by Water Zone and container type. Containers in Water Zones I–II will only drop Special Bait if the "Searching containers yields extra Special Bait" Lucky Bonus is active in those zones.
If the Special Bait Lucky Bonus is active in Water Zones III–V, containers in these zones will drop extra Special Bait in addition to the typical amounts. If this Lucky Bonus is active in Water Zones I–II, containers will only drop the "extra" amount.
Furthermore, Special Bait:
- Can be obtained before unlocking "Kaleido-Catch."
- Does not factor into an operation's total earnings.
- Does not take up Treasure Inventory or Safety Capsule slots, and will always be retrieved in full if the player fails the operation and is forced to use a Safety Capsule.
| Container Type | Standard Special Bait Yield | Lucky Bonus | ||||
|---|---|---|---|---|---|---|
| Zone I | Zone II | Zone III | Zone IV | Zone V | ||
| Investigation Point | – | – | 10 | 15 | 20 | 5 |
| Exquisite Chest | – | – | 15 | 20 | 25 | 10 |
| Exceptional Chest (appears as Precious Chest) |
– | – | 20 | 25 | 30 | 15 |
| Treasured Chest (clamshell chest) |
– | – | 40 | 50 | 60 | 25 |
| Special Challenge Chest (ornate clamshell chest) |
– | – | 60 | 70 | 80 | – |
Lucky Bonuses
Unlocked after completing the Management Commission "VI. Business Benchmark III"
After a successful operation in any Water Zone, each Water Zone will have a random Lucky Bonus applied to it for all subsequent dives until the next successful operation. Lucky Bonuses will not change after failed operations, nor are their effects revoked for the results of a failed operation, so a Lucky Bonus can be taken advantage of by repeatedly failing dives, such as by exiting dives early.
| Lucky Bonus | Notes |
|---|---|
| Increases total operation earnings | Increases earnings from captured targets by 30%,[verification needed] additive with the bonus from Fisher's Fortune.[verification needed] |
| Increases the chance of finding items in containers | – |
| Special investigation sites may appear in the Water Zone | The "Special Challenge" in the Water Zone becomes available. |
| "X" value greatly increased | "X" can be any non-Rampaging Dangerous Creature, including Nemeses. The value of "X" is doubled. |
| Searching containers yields extra Special Bait | See "Special Bait". |
Prismatic Variants
All Dangerous Creatures have a chance to appear as their Prismatic variants instead every time the player enters a Water Zone. Prismatic variants are indicated by sparkles, and if successfully captured, they provide more ![]()
Funds and change their corresponding Archive entry into one with a shining animation.
Operation Failed
A dive can be failed by either abandoning the dive prematurely or losing all Durability. In both cases, if there are items in the Treasure Inventory, the player will be prompted to move as many as they can and want to into the Safety Capsule, which will allow them to bring those items back normally despite the failed dive.
Commissions can still be completed with failed dives, as long as their objectives are completed.
- Operation Failed Messages
One of the following messages will appear if the player fails the challenge by losing all of their Durability.
| Cause | Message |
|---|---|
| Pollution damage | Underwater Threats
Underwater pollution will continue to spread if given time. Once it reaches a certain stage, you will start taking heavy Durability damage over time. Surface from a rendezvous point as soon as possible, or the entire operation may fail... |
| Enemy attacks | Underwater Threats
Observe enemies carefully to learn their attack patterns and behavior, then find the right way to deal with them... |
If the player's backpack is not empty, the following message is also displayed:
- If you fail, you will only be able to bring back some of your items...
Rewards
Phase I
| Objective | Rewards |
|---|---|
| Collect 15 different collectibles in Operation Deep-Dive Treasure | |
| Collect 10 different dangerous creatures in Operation Deep-Dive Treasure | |
| Complete main commission IX: "The Lord of Scrapland's End" | |
| Upgrade "Elite Strike III" in Marvelous Abilities |
Phase II
Complete the Management Commission "XIV. Business Benchmark V" to unlock
| Objective | Rewards |
|---|---|
| Collect 20 different collectibles in Operation Deep-Dive Treasure | |
| Collect 20 different dangerous creatures in Operation Deep-Dive Treasure | |
| Complete main commission XV: "Grease Removal" | |
| Upgrade "Elite Strike V" in Marvelous Abilities | |
| Collect 3 different rampaging dangerous creatures in Operation Deep-Dive Treasure |
Phase III
Complete the Management Commission "XIX. Business Benchmark VII" to unlock
| Objective | Rewards |
|---|---|
| Collect 25 different collectibles in Operation Deep-Dive Treasure | |
| Collect 30 different dangerous creatures in Operation Deep-Dive Treasure | |
| Complete main commission XXI: Business Benchmark VIII | |
| Upgrade "Elite Strike VIII" in Marvelous Abilities | |
| Collect 5 different rampaging dangerous creatures in Operation Deep-Dive Treasure |
Other Languages
| Language | Official Name | Literal Meaning |
|---|---|---|
| English | Operation Deep-Dive Treasure | — |
| Chinese (Simplified) | 巡渊探宝行动 Xúnyuān Tànbǎo Xíngdòng | |
| Chinese (Traditional) | 巡淵探寶行動 Xúnyuān Tànbǎo Xíngdòng | |
| Japanese | サルベージ大冒険 Sarubeeji Daibouken | Salvage Great Adventure |
| Korean | 수중 보물 탐사 Sujung Bomul Tamsa | |
| Spanish | Operación Tesoros Subacuáticos | |
| French | Opération : Trésors aux tréfonds | Operation: Treasure in the Depths |
| Russian | Сокровища глубин Sokrovishcha glubin | |
| Thai | ปฏิบัติการดำดิ่งล่าสมบัติ | |
| Vietnamese | Chiến Dịch Săn Lùng Đáy Biển | |
| German | Schatzsuche in den Tiefen | |
| Indonesian | Operasi Penjelajahan Laut Dalam | Operation Deep Sea Exploration |
| Portuguese | Operação Tesouro das Profundezas | |
| Turkish | Derin Dalış Hazinesi Operasyonu | |
| Italian | Operazione Tesoro in profondità |





































































































