DREDGE The Iron Rig Guide: Facilities, Strange Specimens and DLC Route

DLC scope and first priority

This guide is for The Iron Rig expansion. The rig is a dock and progression hub, not a single late-game shop. Sail due north from The Marrows to J15, dock at the construction rig, and use the Cargo Elevator to meet the Foreman. He marks the missing-shipment wrecks and starts Getting Power. Dredge two Ironhaven Crates from those marked wrecks, return to the rig, and spend both crates on the Generator. That opens the first facility work and makes the new crafting route useful. Do not arrive expecting every infused rod or final hull upgrade to be purchasable immediately; most tiers are tied to the DLC story and regional sample deliveries.

The best way to fit the DLC into a save is to take its next regional task when you are already visiting that region for the base story. It asks for samples from The Marrows, Gale Cliffs, Stellar Basin, Twisted Strand, and Devil’s Spine. Treat each phase as a paired route: fill the requested samples, return to the rig, then decide whether the newly unlocked facility upgrade helps the next region.

Build facilities in story order

After Getting Power, the Foundry, Factory, and Tech Lab become the useful first stops. The Factory begins at Tier 1 and provides the advanced rod blueprints. Completing the first Strange Specimens phase from The Marrows unlocks access to Factory Tier 2; its equipment includes the Siphon Trawler, Material Harvester, and Flotsam Trap. The Gale Cliffs phase then opens the next Factory tier, and the Stellar Basin phase opens the fourth tier and its advanced bait options.

The Foundry handles materials. Its first tier turns one Lumber, one Metal Scrap, and one Bolt of Cloth into an Ironhaven Crate. Its second tier comes after the Gale Cliffs Strange Specimens phase and enables resource refinement. The Tech Lab’s second tier is tied to Contamination, so do not plan around its ability improvements until that story request is complete.

Deliver four samples in each regional phase

The Scientist’s Strange Specimens pursuit is five ordered hand-ins, each asking for four contaminated catches. Deliver the named set to the Science Lab before expecting the next fissure, facility option, or story pursuit.

Region	Four samples
The Marrows	Paddlefish, Osteostracan, Tullimonstrum, Sea Cucumber
Gale Cliffs	Lancetfish, Trilobite, Sollasina, Nautilus
Stellar Basin	Eagle Shark, Kerygmachela, Tripod Spiderfish, Sea Slug
Twisted Strand	Boreapsis, Xiphactinus, Opabinia, Nipponites
Devil’s Spine	Dunkleosteus, Giant Dragonfish, Vetulicolia, Sea Scorpion

Each phase needs the correct Infused habitat tool. The Marrows starter Infused Rod covers the first rod catches; Sea Cucumber still needs a pot in contaminated water. Gale requires an Infused Winch or equivalent Oceanic coverage for Nautilus. Stellar needs an Infused Hoist for Abyssal and Hadal coverage, Twisted Strand needs an Infused Coiling Rod for Mangrove coverage, and Devil’s Spine needs an Infused Fireproof Rod for Volcanic coverage. Do not leave the rig with the previous region’s tool fitted and assume an infused label alone meets every habitat.

Follow the contamination chain when it appears

Contamination needs the Factory at Tier 2 because the Engineer must make the collection equipment. Build the Siphon Trawler with one Basic Trawl Net, one Ironhaven Crate, and $50; install it, collect Dark Fluid and Dark Canisters from contaminated water, then return to the Scientist. This is a tool gate, not a normal fish delivery. If the prompt is present but the Factory cannot build the trawler, finish the Marrows samples first.

Complete the late rig sequence

After the Gale hand-in, take Defend the Rig: speak to the Researcher at Stellar Basin’s Old Fortress, bring the defense information back, and construct the Defenses at the rig. After the Stellar hand-in, the Executive starts The Iron Fleet. Deliver one Ironhaven Crate to construct Fleet Services. Its Tier 5 hull upgrade is optional and costs two more crates plus $2,500; the facility completion, not the hull purchase, advances the route.

After the Twisted Strand hand-in, the Foreman starts Sabotage. Inspect the Defenses, return to the Researcher for the override blueprint, then bring one Ironhaven Crate and one Dark Canister back to the Defenses to override them. This ends the late rig confrontation. Finish building every facility, then return to the Science Lab for the Devil’s Spine four-sample list and the final Strange Specimens resolution. Keep this story chain separate from exotic-aberration hunting and the base ending; use DREDGE Endings for the latter.

Spend crates for the next constraint

Ironhaven Crates are used for facility construction and equipment. Make the needed crate before sailing to the rig, then spend it on the tier that unlocks a current obstacle. Iron Rig Fish and Refining covers infused habitats, contamination catches, and the Foundry’s resource conversions.