All Underwater Shipwrecks — Locations & Loot in AC Black Flag Resynced

All underwater shipwrecks in AC Black Flag Resynced are some of the best optional content in the game. There are 7 dive sites spread across the Caribbean, each loaded with treasure chests and a secret reward worth hunting down. This guide covers every location, how to unlock diving, what you’ll find at each wreck, and tips for surviving the sharks.

TL;DR

• There are 7 underwater shipwrecks (Diving Bell sites) in AC Black Flag Resynced.
• They unlock after completing Sequence 6: Diving for Medicines, which gives you the Diving Bell.
• All 7 shipwrecks hold a total of 68 treasure chests — 61 regular chests and 7 secret chests.
• 6 of the 7 secret chests contain an Ultimate Ship Upgrade Plan for the Jackdaw. The 7th gives you a rare weapon.
• Looting all 68 chests unlocks the Seven Deadly Seas trophy and achievement.
• Each completed wreck turns gold on the world map so you can track progress easily.
• Regular chests pay out around 1,000 Reales each, making shipwrecks one of the fastest money methods in the game.

How to Unlock Underwater Shipwrecks in AC Black Flag Resynced

You cannot access any underwater shipwrecks until you complete Sequence 6, Mission 1: Diving for Medicines. This mission introduces the Diving Bell, a new piece of equipment for the Jackdaw that lets you enter underwater dive zones. The moment the mission ends, all 7 shipwreck locations appear on your world map automatically.

The story takes you straight to the San Ignacio Wreck as part of this mission, so you’ll knock out your first dive while progressing the main campaign. Everything else is optional free-roam content you can tackle in any order from that point on.

If you want to be fully prepared before diving, check out the ship upgrade and customisation guide and the crafting guide to make sure your Jackdaw and gear are in good shape.

How Underwater Shipwrecks Work

Each dive site is marked on the open-world map. You’ll see ship masts sticking out of the water at most locations. Sail up and interact with them to deploy the Diving Bell and drop into the underwater zone.

Once you’re in, you need to swim around and open every chest. Here’s what you need to know:

• Hold L2/LT (or the zoom button on PC) to highlight nearby chests with a white dot. Chests also appear on the mini-map when you’re close enough.
• Every wreck has regular chests (Reales, valuables) and one Secret Chest (a rare weapon or Ultimate Ship Upgrade Plan).
• Watch your breath meter. Refill it at air barrels placed around the site, at air pockets near the surface, or by swimming back to the Diving Bell itself.
• If a shark attacks, dodge sideways the moment you see the white glint on its mouth. That’s the attack telegraph — time your dodge to it.
• Your crew will occasionally drop air barrels into the water to help you out.
• Once a location is fully cleared, its icon turns gold on the world map.

Each dive site also counts as a discovered Location toward the Cartographer trophy, so they’re worth visiting for that reason alone on a completion run.

All Underwater Shipwrecks — Locations and Loot

1. San Ignacio Wreck (348, 744) — Dry Tortuga Region

Chest count: 9 chests (8 regular + 1 secret)
Secret reward: Hull Armor Ultimate Plan
Region: Dry Tortuga

This is the first shipwreck you’ll dive, as the story sends you here during the Diving for Medicines mission in Sequence 6. It’s on the upper west side of the map. After currents push Edward through the caves and into the shark-patrolled open section, head toward the Diving Bell and turn left. Look for a ship with a torn-open side — that’s where the secret chest holding the Hull Armor Ultimate Plan sits. You can loot it during the story mission itself, so don’t miss it on your first visit.

2. Antocha Wreck (600, 634) — Gibara Region

Chest count: 8 chests (7 regular + 1 secret)
Secret reward: Mortars Ultimate Plan
Region: Gibara

The Antocha is one of the more straightforward dives in the game. It’s located south of Nassau in the Gibara region. Most regular chests here pay a flat 1,000 Reales, though one swaps currency for a bundle of jewelry instead. The secret chest contains the Mortars Ultimate Plan, which doubles your ship’s mortar damage — one of the strongest naval upgrades in the game. From the Diving Bell, swim to the southernmost section of the wreck to find it. Watch for the chest tucked at the stern of the ship; it’s easy to swim right past.

3. The Black Trench (184, 429) — Castillo de Jagua Region

Chest count: 8 chests (7 regular + 1 secret)
Secret reward: Espada Ancha (Rare Cutlass)
Region: Castillo de Jagua

The Black Trench is the odd one out in the shipwreck lineup. It’s the only dive site where the secret chest does not contain an Ultimate Ship Upgrade Plan. Instead, you get the Espada Ancha, a rare cutlass. If your only goal is maxing out the Jackdaw, this site won’t help your ship — but the weapon is worth it if you prefer aggressive melee builds. All chests here are straightforward once you sweep the wreck using the L2/LT zoom highlight.

4. La Concepción Wreck (150, 271) — Chinchorro Region

Chest count: 10 chests (9 regular + 1 secret)
Secret reward: Round Shot Strength Ultimate Plan (also referenced as Cannon Shot)
Region: Chinchorro

La Concepción sits in the Chinchorro region and holds 10 chests — one of the higher counts in the game. With more chests to find, you’ll be underwater longer, so keep a close eye on your breath meter between air pockets. Head down through the seaweed section on entry and work through the wrecked ship hulls systematically. The secret chest holds the Round Shot Strength Ultimate Plan, a major upgrade to your main cannons’ damage output.

5. Devil’s Eye Cavern (453, 323) — Cruz Region

Chest count: 11 chests (10 regular + 1 secret)
Secret reward: Swivel Guns Ultimate Plan
Region: Cruz (north of Charlotte)

Devil’s Eye Cavern is located directly north of Charlotte in the Cruz region. With 11 chests, this is one of the richest dive sites for pure money — almost every regular chest here contains jewelry and valuables rather than flat Reales, which adds up to considerably more total income than a standard Reales chest. The cavern layout twists more than open wrecks, so lean on your chest map markers as you swim. For the secret chest, head north through the tunnels into the open cave section. A tunnel on the left leads down to a dry alcove where the Swivel Guns Ultimate Plan is waiting, increasing your ship’s gunwale damage by 150%.

6. The Blue Hole (440, 145) — Charlotte Region

Chest count: 11 chests (10 regular + 1 secret)
Secret reward: Broadside Cannons Number Ultimate Plan
Region: Charlotte

The Blue Hole is in the Charlotte region and ties Devil’s Eye Cavern for the second-highest chest count in the game. Watch out for jellyfish on the approach — they’re more of an environmental hazard here than at other sites. Swim to the far northern end of the dive and check the broken-open wreck at ground level. The secret chest sits tucked beneath the hull and contains the Broadside Cannons Number Ultimate Plan, which raises your broadside cannon capacity to 18. That’s one of the most impactful Jackdaw upgrades for naval combat.

7. Kabah Ruins (739, 117) — Navassa Region

Chest count: 12 chests (11 regular + 1 secret)
Secret reward: Round Shot Strength Ultimate Plan (some sources list as Cannon Strength)
Region: Navassa (east side of the map)

Kabah Ruins holds the most chests of any dive site at 12, making it the most valuable haul in the game if you’re farming Reales. It’s on the east side of the map. Enter the cave at the northern point of the dive map and push through the tunnels. You’ll hit a strong underwater current at one point that blocks part of the route — don’t try to swim through it. Take shelter in the small side cave on the right, wait for the current to ease, then refill your air at the oxygen pockets in nearby rooms before pushing forward. The secret chest is deep inside and worth the detour.

Seven Deadly Seas Trophy and Achievement

Opening all 68 treasure chests across all 7 underwater shipwrecks unlocks the Seven Deadly Seas trophy on PlayStation and achievement on Xbox and PC. Here’s the full chest breakdown by location:

• San Ignacio Wreck: 9 chests
• Antocha Wreck: 8 chests
• The Black Trench: 8 chests
• La Concepción Wreck: 10 chests
• Devil’s Eye Cavern: 11 chests
• The Blue Hole: 11 chests
• Kabah Ruins: 12 chests
• Total: 69 chests (61 regular + 7 secret + 1 bonus)

Once a location is fully cleared, its icon on the world map turns gold. Use that as your tracker — any site still showing a standard icon still has chests you haven’t opened.

All Shipwreck Secret Chests and Ultimate Plans — Summary

• San Ignacio Wreck (348, 744): Hull Armor Ultimate Plan
• Antocha Wreck (600, 634): Mortars Ultimate Plan
• The Black Trench (184, 429): Espada Ancha rare cutlass (no ship plan)
• La Concepción Wreck (150, 271): Round Shot Strength Ultimate Plan
• Devil’s Eye Cavern (453, 323): Swivel Guns Ultimate Plan
• The Blue Hole (440, 145): Broadside Cannons Number Ultimate Plan
• Kabah Ruins (739, 117): Cannon Strength Ultimate Plan

Once you have all six ship plans, you’ll need to take them to the Harbourmaster to unlock the final purchase tier for each upgrade. You can’t buy the ultimate upgrades without the plan — finding the physical plan is the gate.

For the full picture on all 12 Ultimate Ship Plans (including the 6 from treasure maps), check our Final Ship Upgrade Locations and Ultimate Plans guide.

Best Diving Tips for AC Black Flag Resynced

• Use the zoom highlight constantly. Hold L2/LT (or the equivalent on PC) while underwater. It reveals every nearby chest as a white dot. Without it, chests blend into the environment easily.
• Check the mini-map. Chests appear as icons when you’re swimming nearby. Use both the highlight and the mini-map together so you don’t miss anything.
• Dodge sharks sideways. When a shark attacks, watch for the white glint that appears on its mouth. That’s the attack signal. Dodge sideways the moment you see it. Fighting sharks wastes breath — dodge and move on.
• Prioritise air barrels. Your crew drops air barrels in the water to help you. Interact with them, air pockets, and the Diving Bell itself to refill your breath. At sites with 11 or 12 chests like Devil’s Eye Cavern and Kabah Ruins, you’ll need to manage your air carefully between clusters of chests.
• Don’t skip Black Trench. Even though it has no Ultimate Plan, it still counts toward the Seven Deadly Seas trophy and gives you the Espada Ancha cutlass. You need all 7 cleared for the achievement.
• Prioritise by need. If you’re struggling in naval combat early, head to Kabah Ruins and The Blue Hole first for Cannon Strength and Broadside Cannons upgrades. Those two make the biggest difference in tough ship fights.

Are Shipwrecks Worth It for Money?

Yes — clearing all 61 regular chests earns you roughly 61,000 Reales, plus the value of any jewelry you sell on top of that. Devil’s Eye Cavern is especially good for jewelry hauls since almost every chest there drops valuables rather than flat cash. Combined, the 7 shipwrecks represent one of the fastest legitimate money methods in the early and mid-game before you have other income streams running.

For more money farming tips, see our guide on how to farm metal and wood and the Kenway’s Fleet guide for a longer-term income strategy.

More AC Black Flag Resynced Guides

• All Animus Rifts — Locations and Walkthrough
• How to Beat All 6 Legendary Ships
• Legendary Ships Mortar Trick
• How to Fast Travel
• All Treasure Map Locations
• All Mayan Stelae Locations
• Forts Guide
• How to Capture Forts
• Beginner’s Tips
• How Long to Beat

Where to Buy AC Black Flag Resynced

• PlayStation Store
• Xbox Store
• Steam
• Epic Games Store

Frequently Asked Questions