DLC Guide: Find Every New Fish and Aberration in Dredge: The Iron Rig

Last Updated on 1 December, 2025

This expansion introduces a sinister new storyline, industrial mechanics, and a host of deep-sea oddities to collect. Whether you aim to upgrade your vessel to its industrial peak or hunt down every new aberration, this guide covers every necessary step. The Iron Rig expansion adds significant depth to the game. You face a new mystery involving the Ironhaven Corporation and a creeping contamination spreading across the waters. Completing this content requires more than just fishing skills. You must manage complex upgrade trees, navigate hazardous oil spills, and survive encounters with primordial beasts.

We have compiled all the necessary information to help you unlock every achievement in the expansion. You will find detailed instructions for story milestones, collection tasks, and the complete list of new fish species required for your encyclopedia. This guide prioritizes efficiency and accuracy to help you secure that 100% completion rating.

Use the table of contents below to navigate directly to the specific achievement you need.

General Tips and Preparation

Success in The Iron Rig requires careful preparation. The expansion centers on the rig itself, which serves as a new hub area. You will frequently travel between this hub and the five major regions of the game to collect materials and fish. This back-and-forth travel can become tedious without the right tools.

If you own the The Pale Reach DLC, we strongly recommend you utilize the Aurorus Anchor. This item allows you to create a portable teleportation point. Place this anchor at the foot of the Iron Rig to cut down significant travel time. You can warp back to the rig to offload cargo or upgrade your ship and then return to your previous fishing spot manually. This strategy streamlines the process of completing fetch quests and managing your inventory.

You should also prioritize managing your cargo space. The new Ironhaven Crates take up significant room in your hold. These crates serve as the primary currency for upgrading the rig structures. Ensure you upgrade your hull size as quickly as possible to maximize the number of crates you can transport in a single trip.

Story and Upgrade Achievements

This section covers achievements related to the main progression of the Iron Rig storyline. You will earn most of these naturally by advancing the plot and purchasing the various upgrades available for your boat and the rig itself.

Missing Shipment

You unlock this achievement early in the expansion. It serves as an introduction to the crate retrieval mechanic. Your task involves delivering a lost Ironhaven crate to the Foreman on the rig. Pilot your boat just southwest of the rig structure to find a specific wreckage site.

The map marks this location with a small golden oil rig stamp to distinguish it from standard material spots. Dredge the wreckage to retrieve the crate. Once you have the item secure in your cargo, return it to the Foreman. The achievement triggers as soon as you complete the delivery.

Remedial Apparatus

The Iron Rig introduces hazardous oil spills that block fishing spots and damage your hull. Progression through the story unlocks new equipment options to deal with these environmental hazards. To earn the Remedial Apparatus title, you must purchase and equip the Siphon Trawler.

You must first construct the Tier 2 Factory on the rig. Visit the Engineer at this new facility to find the Siphon Trawler in the shop inventory. This net allows you to clean up oil spills while you sail. Once you purchase the item and install it in a net slot on your boat, the achievement will trigger.

Enhanced Abilities

The Iron Rig offers superior technology for your vessel to help you survive the gloomier atmosphere of the DLC. Visit the Engineer at the Tier 1 Tech Lab to view their specialized stock. You need to upgrade three specific boat components to unlock this achievement.

Purchase the upgraded light, the foghorn, and the spyglass from the Tech Lab. These items provide better visibility in the fog and allow you to spot distant disturbances more easily. Buying all three items adds this accolade to your collection. You do not need to equip them simultaneously, but owning them is mandatory.

Hull: Industrial

This achievement represents the pinnacle of boat progression in Dredge. You must upgrade your boat to its absolute maximum level. This involves a long series of upgrades and a significant investment of resources. Advance the main story until you meet the Ironhaven Executive. He will eventually grant you permission to construct the Fleet Services building.

This facility allows you to access the final hull upgrade tier. Be prepared to pay a significant price. The upgrade costs several Ironhaven crates and approximately $2500 in cash. We recommend spending time fishing for high-value species or using trawl nets to generate passive income to afford this fee. Purchasing this upgrade permanently transforms your hull into an industrial vessel and unlocks the achievement.

Rig Architect

To become the Rig Architect, you must fully upgrade the Iron Rig itself. This task requires you to purchase every tier for every building available on the rig. This process demands a massive number of Ironhaven Crates. You cannot rely solely on finding crates in floating wreckage to complete this quickly.

For a faster method, invest in the Material Trawl Net as early as possible. This net passively collects materials needed to craft Ironhaven Crates while you sail between locations. Additionally, you can visit Ironhaven wreckages periodically to dredge up extra crates. Combining passive collection with active dredging is the most efficient way to gather the necessary resources.

The Iron Ruin

This is a hidden achievement tied to a specific story choice near the end of the DLC. You must sabotage the defense system of the rig. To do this, continue the story until the narrative requires the Override Blueprint.

You can acquire this blueprint from the Scientist located in the Stellar Bay. The item costs one Ironhaven crate and one dark canister. Bring these items to him to receive the blueprint. Once you have the blueprint, return to the rig and execute the sabotage. The achievement unlocks immediately after you perform this action.

Collection and Gameplay Achievements

These achievements challenge you to interact with the hazardous oil mechanic and the monsters it spawns. These tasks often require you to put your boat in danger, so proceed with caution.

Shadowed Splashes

This task involves a bit of calculated risk. You must collect five dark splashes, which are items that result from volatile oil interactions. Head to an oil spill and locate a bubbling oil patch. Alternatively, you can find oil nightmares, which are aggressive entities that resemble enemies from other franchises.

Allow an oil bubble to burst near your boat. You can also let a nightmare creature explode in your vicinity. This action generates a dark splash item in the water. Dredge or scoop it up quickly. Be careful during this process because collecting these items negatively impacts your sanity meter. Gather five of them to complete the requirement.

Dark Custodian

For this achievement, you need to manufacture 10 dark canisters. The Iron Rig uses these canisters for various high-tier upgrades. Utilize your Siphon Trawler to harvest oil from the various spills scattered around the map.

The equipment automatically converts the collected oil into a dark canister once you gather enough volume. You do not need to do anything other than sail through the muck with the net deployed. Repeat this process until you have created 10 canisters total. The game tracks the total number crafted, so you do not need to hold all 10 in your inventory simultaneously.

The Gleaming Goliath

This achievement requires you to bait and evade a massive monster known as the Gleaming Goliath. This is arguably the most skill-dependent achievement in the DLC. Navigate your boat into a dense oil field while your sanity is very low. You need high panic levels to trigger the encounter.

You might see oil squids or tentacles initially. Ignore them and wait for the large oil amalgamation to appear. The creature moves slowly, so you can outmaneuver it with your engines. To unlock the achievement, you must trick the monster into performing its lunge attack animation without it hitting you.

Wait for the creature to wind up for a strike. Use the Haste ability right before the attack connects to speed out of range. Alternatively, use the Banish power-up to repel it mid-lunge. If the creature lunges and misses your hull completely, the game grants you the achievement.

Fishing and Encyclopedia Achievements

A significant portion of the DLC involves catching new species. The expansion adds fish to every major region of the game. The following sections detail where to find every new fish and aberration.

Exotic Exemplar

You need to catch a single exotic aberration to earn this title. Exotic fish are usually very rare, but the Iron Rig update simplifies this process with the introduction of specific baits. Purchase Exotic Bait from the Engineer on the rig.

Travel to a region that contains an exotic fish you have previously discovered. Toss the bait into the water to attract the fish. Do not fish for it normally. Instead, immediately use the Atrophy power-up. This ability pulls the fish from the water instantly and guarantees an aberration catch. This method secures the achievement without relying on luck.

Ancient Angler

This achievement requires you to catch every new base species of fish introduced in the update. The contamination has caused new prehistoric species to appear in oil spills across the map. If you struggle to find a specific fish in one oil spill within a region, check the other spills in the same area.

The Marrows:

• #11 Osteostracan: Found in oil spills.
• #12 Tullimonstrum: Found in oil spills.
• #13 Paddlefish: Found in oil spills.
• #14 Swordfish: Found in open water near spills.
• #17 Sea Cucumber: You must catch this using a Crab Pot placed in the oil.

The Gale Cliffs:

• #27 Nautilus: Found in oil spills.
• #28 Sollasina: Found in oil spills.
• #29 Abyssal Gar: Found in oil spills.
• #30 Lancetfish: Found in oil spills.
• #33 Trilobite: You must catch this using a Crab Pot.

The Stellar Bay:

• #47 Mahi Mahi: Found in oil spills.
• #48 Tripod Spiderfish: Found in oil spills.
• #49 Kerygmachela: Found in oil spills.
• #50 Eagle Shark: Found in oil spills.
• #54 Sea Slug: You must catch this using a Crab Pot.

The Twisted Strand:

• #61 Opabinia: Found in oil spills.
• #62 Boreaspis: Found in oil spills.
• #63 Arapaima: Found in oil spills.
• #64 Xiphactinus: Found in oil spills.
• #67 Nipponites: You must catch this using a Crab Pot.

The Devil’s Spine:

• #74 Vetulicolia: Found in oil spills.
• #75 Sawfish: Found in oil spills.
• #76 Giant Dragonfish: Found in oil spills.
• #77 Dunkleosteus: Found in oil spills.
• #81 Sea Scorpion: You must catch this using a Crab Pot.

Primordial Deviations

Your final major task regarding the encyclopedia is to catch every new aberration variant. This takes time. The rod-based fish are straightforward, as you can use bait and the Atrophy ability to force aberrations. However, the crab pot species present a unique challenge because you cannot force aberrations on pots as easily.

A helpful community strategy suggests using the infection mechanic. Place a normal crab next to an infected fish in your cargo hold. The infection can spread from the fish to the crab. This transformation causes the crab to become its aberrant version. This method is often faster than waiting for a random aberration spawn in a pot.

The Marrows Aberrations:

• #123 Plated Osteostracan
• #124 Axial Matron
• #125 Anvilfish
• #126 Ivory Impaler
• #129 Inverted Husk (Crab Pot variant)

The Gale Cliffs Aberrations:

• #142 Clutching Nautilus
• #143 Vagrant Sollasina
• #144 Bifurcated Gar
• #145 Silvering Lancetfish
• #148 Cystic Trilobite (Crab Pot variant)

The Stellar Bay Aberrations:

• #165 Xeno Xeno
• #166 Stalking Spiderfish
• #167 Drifting Chrysalis
• #168 Sanguine Shark
• #172 Mimic Slug (Crab Pot variant)

The Twisted Strand Aberrations:

• #181 Crawling Instar
• #182 Boreal Shell
• #183 Broken Arapaima
• #184 Primordial Shadow
• #187 Wretched Nipper (Crab Pot variant)

The Devil’s Spine Aberrations:

• #195 Unveiled Vetulicolia
• #196 Plated Barbjaw
• #197 Untouchable Wyrmfish
• #198 Excoriated Fiend
• #202 Erupting Scorpion (Crab Pot variant)

Bonus: The Scientist and Fish #230

Players wondering about the ultimate fate of the Scientist can uncover a final secret. This is not strictly an achievement listed on Steam, but it serves as a bonus objective for completionists. You can encounter Fish #230 by using aberration bait near the rig, but you must adhere to strict conditions to trigger the event.

1. Complete the DLC Narrative

You must finish all of the Scientist’s fetch quests first. The story must be complete before this entity appears.

2. Prepare Your Gear

Equip the Hydraulic Rod. While other items like the Radiant Trawl Net and Encrusted Talisman are helpful for stats, the Hydraulic Rod is the essential tool for oceanic fishing in this context. Remove other rods from your boat to narrow the pool of potential fish. If you have too many rod types equipped, you might attract the wrong species.

3. Location and Method

Dock at the Iron Rig and save your game. This step is crucial because the resource cost for the attempt is high. Craft at least five units of aberration bait. Undock and throw the bait into the water near the rig. You do not need to be directly under the drill. Anywhere near the main structure works.

4. Persistence

The chance to find this catch is very low. You might go through all your bait without seeing it. If you burn through your bait without success, reload your save file and try again. This save scumming method saves you the time of grinding for more bait materials.

5. Secret Lore

If you manage to catch Fish #230 while your panic level is high, the game reveals a hidden description. It speaks of elder blood and the true Deep, offering a final piece of narrative flavor for those brave enough to fish in the dark.

Conclusion

Congratulations on navigating the dark, oil-slicked waters of Dredge: The Iron Rig. By following these steps, you now possess the knowledge to fully upgrade your fleet, document every ancient horror, and uncover the final secrets of the deep.

The journey requires patience, especially regarding the crate grinding and the rare aberration catches. However, the reward is a fully completed encyclopedia and a boat capable of withstanding anything the ocean throws at it. Good luck with your dredging, and may your sanity hold long enough to see 100% completion!