TL;DR
- The AC Black Flag Resynced Antocha Wreck is located at coordinates (600, 635), south of Nassau in the Gibara region.
- It is an underwater shipwreck accessible only after unlocking the Diving Bell in Sequence 6 — Mission “Diving for Medicines.”
- There are 8 total collectibles: 7 regular treasure chests and 1 secret chest.
- The secret chest (Chest 3) contains the Mortars Ultimate Plan — one of the most important ship upgrades in the game.
- Sharks and jellyfish patrol the wreck — manage your air supply using air barrels and the Diving Bell.
- You cannot heal underwater, so go in with full health.
The AC Black Flag Resynced Antocha Wreck is one of the richest underwater locations in the whole game. It holds 8 collectible chests spread across multiple wrecked ships on the ocean floor, including the Mortars Ultimate Plan hidden in a secret chest. The trouble is navigating the layout while managing sharks, jellyfish, limited air, and zero ability to heal. Miss a turn or take a wrong path and you might surface with nothing but a half-dead Edward. This guide covers every chest in order, including exactly where to swim, so you can clean out the Antocha Wreck in a single dive.
If you enjoy these underwater locations, we also have a complete guide for the Anotto Bay chests and secret locations which uses a similar cavern dive format with its own set of tricky collectibles to find.
Antocha Wreck Location & How to Access It
The Antocha Wreck sits at coordinates (600, 635) in the Gibara region, directly south of Nassau. It is one of the seven underwater shipwrecks that Edward can explore in AC Black Flag Resynced.
You cannot access any underwater shipwreck until you complete the main mission “Diving for Medicines” in Sequence 6. This mission unlocks the Diving Bell, which is the only way to descend into wrecks. Once that mission is done, you can revisit the Antocha Wreck any time you like from the open world.
To start the dive, sail to the coordinates and look for the Diving Bell floating on the surface. Interact with it to descend. You’ll drop down into the wreck area where the chests are waiting.
Before You Dive — Key Tips
- Fill Edward’s health completely before going under. You cannot use healing items while diving.
- Watch the air meter at all times. When it runs low, swim to an air barrel to refill. You can also return to the Diving Bell itself to top up your air.
- Sharks patrol the wreck — keep an eye on the detection wheel. Dodge their charges by swimming to the side at the right moment.
- Jellyfish also deal damage — avoid swimming directly into them.
- Plan your route. Following the chest order in this guide will save you backtracking and wasted air.
Antocha Wreck — All 8 Chest Locations
Chest 1 — Right at the Entry Point (1,200 Reales)
As soon as Edward descends through the Diving Bell, the first chest is directly ahead of him. Swim forward a short distance and dive down slightly. You will see the broken hull of a small shipwreck sitting on the sea floor. The chest is inside the destroyed deck below. Open it before moving anywhere else.
Reward: 1,200 Reales
Chest 2 — Across the Reef from Chest 1 (1,200 Reales)
From Chest 1, turn and swim through the reef directly ahead of you. The second shipwreck is just on the other side. The chest sits inside the wrecked structure — you will see it clearly once you pass the reef. It mirrors the first chest in layout.
Reward: 1,200 Reales
Chest 3 (Secret) — Mortars Ultimate Plan
This is the most important chest in the entire wreck. After collecting Chest 2, swim south until you reach a third shipwreck. This one has a larger chest sitting on its destroyed deck — it is slightly bigger than the regular chests and visually distinct.
Opening this chest gives you the Mortars Ultimate Plan — one of the final Jackdaw upgrade blueprints in the game. If you are working toward the final ship upgrade locations guide, this is one of the key plans you need to fully upgrade the Jackdaw’s mortar system.
Reward: Mortars Ultimate Plan
Chest 4 — Top Deck of the Third Wreck (1,200 Reales)
Do not leave the third shipwreck yet. After grabbing Chest 3 from the lower deck, swim upward to the wrecked ship’s top deck. Once you get up there, look beneath the broken and splintered boards on the deck surface. Chest 4 is tucked below the broken planks — easy to miss if you go straight back to the surface.
Reward: 1,200 Reales
Chest 5 — Sea Bed Past the Large Hull (Jewelry)
From Chest 4, swim north toward the large shipwreck in the area. Dive further down as you approach it. Once you pass the large destroyed hull section of this bigger ship, look down at the sea floor on the other side. Chest 5 is sitting right there on the bed, in the open.
Reward: Emerald (230 Reales), Silver Bracelet (380 Reales), Gold Tiara (370 Reales) — total 980 Reales in jewelry
Chest 6 — Inside the Large Ship’s Hull Cabin (Jewelry)
Chest 6 is inside the same large shipwreck from Chest 5. After picking up the sea floor chest, swim upward and enter the destroyed hull of the big ship. There are two entry points into the hull — take the one on the right. The left entrance is boarded up.
Once inside, keep swimming forward and take a U-turn to the left to enter one of the ship’s interior cabins. Chest 6 is waiting at the far end of that cabin.
Reward: Sapphire Earrings (420 Reales), Diamond Earrings (450 Reales), Silver Bracelet (160 Reales) — total 1,030 Reales in jewelry
Chest 7 — Crew Cabin on the Top Deck (1,200 Reales)
After grabbing Chest 6 from the cabin, swim upward to the ship’s top deck. Head toward the middle of the staircase and go inside the crew cabin. Swim to the back of the room and Chest 7 is sitting there. This one is straightforward once you know to look in the crew cabin and not on the outer deck.
Reward: 1,200 Reales
Chest 8 — Northeast Hull Breach (Jewelry)
The last chest is on the outer hull of the large ship. Exit the crew cabin and swim around to the northeast corner of the ship. You are looking for a hole in the side of the hull — a breach large enough for Edward to swim through. Go inside through this opening and Chest 8 is right there in the hull interior.
Reward: Gold Tiara (370 Reales), Sapphire Earrings (420 Reales), Gold Chain (270 Reales) — total 1,060 Reales in jewelry
All Antocha Wreck Collectibles at a Glance
Here is a quick reference for all 8 chests in order:
- Chest 1 — Entry point, small wreck ahead, open deck below — 1,200 Reales
- Chest 2 — Through the reef from Chest 1, second small wreck — 1,200 Reales
- Chest 3 (Secret) — Swim south to third wreck, large chest on deck — Mortars Ultimate Plan
- Chest 4 — Top deck of third wreck, under broken boards — 1,200 Reales
- Chest 5 — Sea floor past the large hull, open water — Emerald, Silver Bracelet, Gold Tiara
- Chest 6 — Inside large hull cabin, enter right side, U-turn left — Sapphire Earrings, Diamond Earrings, Silver Bracelet
- Chest 7 — Top deck crew cabin, back of the room — 1,200 Reales
- Chest 8 — Northeast hull breach, swim inside — Gold Tiara, Sapphire Earrings, Gold Chain
Why the Mortars Ultimate Plan Matters
The Mortars Ultimate Plan from Chest 3 is not just a random piece of loot. It is one of the 12 Ultimate Plans needed to fully upgrade the Jackdaw — the most powerful ship upgrade tier available. Without it, your mortar system stays at a lower level and you will feel the gap when fighting Legendary Ships.
If you are going for full ship upgrades, the Legendary Ships mortar trick guide is worth reading alongside this — it explains how to use your mortars most effectively in those tough boss fights once your Jackdaw is properly upgraded.
Air Management Strategy for the Antocha Wreck
The biggest challenge in the Antocha Wreck is not the sharks — it is running out of air. Here is how to handle it efficiently:
- Collect Chests 1 and 2 first, then return to the Diving Bell to top up your air before heading south.
- Look for air barrels scattered around the wreck. They glow slightly and are usually tucked near structures. Swim into them briefly to refill.
- The large shipwreck area (Chests 5 through 8) has enough air barrels nearby to get through all four chests if you are efficient about it.
- Do not panic-sprint. Rushed swimming wastes time on navigation and does not actually deplete air faster.
Other Underwater Shipwrecks Worth Exploring
Antocha Wreck is one of seven underwater shipwrecks in AC Black Flag Resynced, and they all follow a similar formula with chests, a secret, and sharks to dodge. Here are the others you should visit:
- The San Ignacio Wreck — also unlocked after Sequence 6, with 7 chests and its own secret.
- The Black Trench Wreck — another Gibara region dive worth completing for full collectible coverage.
- The Blue Hole — a different kind of underwater area with its own layout and rewards.
- For a full map of every underwater site, the all underwater shipwrecks locations and loot guide lists them all with coordinates and reward summaries.
Where to Get Assassin’s Creed Black Flag Resynced
New to the game or looking to add it to another platform? Here are all the official purchase links:
Wrapping Up
The AC Black Flag Resynced Antocha Wreck rewards patience and a good sense of direction. The 8 chests follow a logical south-to-north route through the wrecked ships, and once you know where each one sits, a single well-managed dive is enough to clean up 100% of the collectibles. The Mortars Ultimate Plan alone makes this one of the most essential shipwreck dives in the game — especially if you are building up the Jackdaw for the Legendary Ship fights ahead.
If you are chasing full completion across every region, the Animus Keys locations guide and the character portraits guide are great next stops to keep that progress tracker moving.
