Antocha Wreck Walkthrough – Assassin’s Creed Black Flag Resynced

TL;DR

• Antocha Wreck is in the Gibara region at coordinates 600, 636
• It’s an optional dive — unlocked after completing Diving for Medicines in Sequence 6
• There are 7 standard chests and 1 secret chest to collect — all 8 for 6,910 Reales plus the Mortars plan
• The secret chest rewards the Mortars Ultimate Plan — one of the best ship upgrades in the game
• One chest near the stern is easy to miss — you have to swim outside the ship to reach it
• If your map shows 7/7 chests but the location is still incomplete, you still need the secret chest in the southernmost debris piece
• Sharks patrol the area, so stick to kelp and seaweed on the west side for cover

The Antocha Wreck walkthrough in Assassin’s Creed Black Flag Resynced covers one of the most rewarding optional dives in the whole game. Hidden inside a submerged shipwreck in the Gibara region, this location holds 7 standard chests and a secret chest containing the Mortars Ultimate Plan — a key upgrade that massively boosts your Jackdaw’s firepower. The wreck also has one notoriously tricky chest that trips up a lot of players. This guide covers the exact location, a step-by-step walkthrough, every chest position, and tips to survive the dive.

Antocha Wreck Location

The Antocha Wreck sits in the Gibara region at coordinates 600, 636. Sail there and look for ship masts poking up from the ocean surface. Pull up alongside them with the Jackdaw and interact with the prompt to lower your Diving Bell and descend.

Unlike the San Ignacio Wreck, this one is entirely optional — the story never sends you here. You’ll need to seek it out yourself after the Diving Bell is unlocked.

How to Unlock the Antocha Wreck

You can only dive at the Antocha Wreck after completing Diving for Medicines, the first memory in Sequence 6. That mission gives you the Diving Bell and automatically marks all shipwrecks on your map, including this one.

If you haven’t done that mission yet, head there first. Our San Ignacio Wreck walkthrough covers the story mission in full and also explains how to unlock diving in general.

Antocha Wreck

Antocha Wreck Walkthrough – All Chest Locations

The wreck is split into two main halves — the stern (northern half) and the bow (southern half) — plus several smaller broken shipwreck pieces scattered nearby. Four of the eight chests are tucked inside the two main hull sections and are the hardest to reach. The remaining four are spread across the smaller debris around the Diving Bell. Follow this route: start at the northwest and center debris pickups near the Diving Bell, then work through the main stern and bow sections, and finish at the southernmost debris piece where the secret chest is.

Stern Section Chests (Northern Half)

These four chests are buried inside the northern stern wreckage and require some navigation to reach. Start here as they take the most effort.

Chest 1 — At the very bottom of the south edge of the stern section. This is the lowest point of the northern half. Swim all the way down to the sea floor and look along the bottom of the hull.

Chest 2 — Inside a small room on the middle deck of the stern wreckage. Swim into the deck, take the second left, then turn left again. The chest is in the room at the end.

Chest 3 — Deep inside the stern on the upper deck. From Chest 2, turn around and go straight ahead, then swim up to the next deck. The chest is directly ahead of you.

Chest 4 (The Tricky One) — This is the one that trips people up. It’s accessed through a corridor at the east corner of the stern, roughly halfway down the ship. Look for an opening on the exterior of the hull surrounded by a shoal of fish, coral, and plants. Swim through that gap and the chest is at the end of the corridor inside. If you’ve been hunting inside the ship and can’t find it, swim outside to the stern’s exterior wall and look for the missing chunk of hull — that’s your entrance.

Bow Section Chest (Southern Half)

Chest 5 — On the top deck of the southern bow half of the wreck, near the bowsprit (the forward-pointing beam at the front of the ship). Swim up and over the top of the bow section to grab it.

Small Debris Chests (Near the Diving Bell)

Three chests are inside the smaller broken shipwreck pieces scattered around the Diving Bell. These are much easier to find once you use L2/LT to scan for white dots.

Chest 6 — Inside the small shipwreck piece closest to the Diving Bell.

Chest 7 — Inside the small shipwreck piece directly south of the Diving Bell.

Secret Chest (Mortars Ultimate Plan) — Inside the small shipwreck piece furthest from the Diving Bell, at the southernmost point of the dive site. This is the one you really want. Swim to the southernmost broken debris section and look for a broken hull section with an air barrel floating just outside. Go inside along the left wall and open the large chest to collect the Mortars Ultimate Plan.

Troubleshooting: If your map shows 7/7 chests complete but the Antocha Wreck location is still showing as incomplete, you haven’t collected the Secret chest — it is tracked separately from the seven standard chests. Return to the southernmost debris piece and open the large Secret container there. If your map shows 6/7, the missing chest is most likely Chest 4 — the one accessed from the exterior opening on the east side of the stern hull.

Antocha Wreck All Chests and Rewards

Here’s a full list of every chest and what you’ll get from each one.

• Chest 1 – Reales (south base of stern)
• Chest 2 – Reales (middle deck, stern interior)
• Chest 3 – Reales (upper deck, stern interior)
• Chest 4 – Reales (east corridor, accessed via exterior hull gap)
• Chest 5 – Reales (top deck of bow section)
• Chest 6 – Reales (debris near Diving Bell)
• Chest 7 – Reales (south of Diving Bell)
• Secret Chest – Mortars Ultimate Plan (furthest debris piece from Diving Bell)

All seven standard chests together pay out 6,910 Reales in total, on top of the Mortars plan from the secret chest. Diving is one of the fastest money-making methods in the game. If you’re looking for more resource tips, check out our guide on how to farm metal and wood for Jackdaw upgrades.

What Does the Mortars Ultimate Plan Do?

The Mortars Ultimate Plan unlocks the Mortar IV upgrade for the Jackdaw, which increases your auxiliary weapon damage to 300%. Mortars are already strong against large ships and forts — this upgrade makes them devastating.

To actually buy the Mortar IV upgrade after getting the plan, you’ll need a Tier 3 Harbourmaster at Great Inagua, plus 25,000 Reales and 650 Metal. The plan itself is just the unlock — the materials still need to be gathered. See our Great Inagua upgrades guide for how to push your Harbourmaster to Tier 3 first.

For a broader look at every Ultimate Plan across the whole game, check out our final ship upgrade locations and Ultimate Plans guide.

Tips for Surviving the Antocha Wreck Dive

• Stick to the west side of the wreck — There’s a lot of kelp and seaweed on the west side that provides cover from the sharks patrolling the area. Stay low and use it.
• Watch for jellyfish as well as sharks — The waters around the Antocha Wreck contain both sharks and jellyfish. You cannot heal during a dive, so avoid contact with both. Sharks can be dodged on the white glint as they charge; jellyfish should be simply swum around.
• Use L2/LT to scan constantly — The white dot system highlights nearby chests even inside dark hull sections. Hold it as you explore to avoid missing anything.
• Save air barrels for emergencies — Barrels are one-use only per dive. Don’t waste them when you still have decent breath. The air barrel near the secret chest is handy — use it if you’re running low before grabbing the Mortars plan.
• Dodge sharks on the white glint — Watch the shark’s mouth as it charges. The moment you see the white flash, dodge sideways. Reacting before or after gets you hit.
• Check the exterior for Chest 4 — If your map still shows an uncollected chest and you’ve swept the inside of the stern, swim to the outside of the hull and look for the opening there. That’s the one most players miss.
• Check your underwater map often — The map updates as you get close to chests and marks them, which helps you track what you’ve already grabbed.

Seven Deadly Seas Trophy / Achievement Progress

The Antocha Wreck contributes 7 standard chests and 1 secret chest to the Seven Deadly Seas trophy and achievement. Visiting the wreck also counts as a discovered Location, adding progress toward the Cartographer trophy.

Our full underwater shipwrecks locations and loot guide has everything you need to track all shipwrecks and every chest across all dive sites.

What to Do After the Antocha Wreck

With the Mortars Ultimate Plan in hand, the next best wrecks to tackle are The Blue Hole at 440, 145 for the Broadside Cannons Number Ultimate Plan, and La Concepción Wreck in Chinchorro for the Ram Ultimate Plan. The San Ignacio Wreck in Dry Tortuga holds the Hull Armor Ultimate Plan if you haven’t grabbed that yet. All are worth doing before you take on the Legendary Ships.

If you want to keep building out your Caribbean empire, check out our guides on all naval contract locations, how to capture forts, and ship upgrades and customisation.

If you haven’t picked up the game yet, it’s available on PlayStation Store, Xbox, Steam, and Epic Games Store.

More AC Black Flag Resynced Guides

• San Ignacio Wreck Walkthrough
• All Underwater Shipwrecks Locations and Loot
• How to Beat All 6 Legendary Ships
• Legendary Ships Mortar Trick
• Crafting Guide
• Great Inagua Upgrades Guide
• Kenway’s Fleet Guide
• All Assassin Contracts Locations
• All Treasure Map Locations
• Beginner’s Tips

Frequently Asked Questions