AC Black Flag Resynced Ultimate Plans — All 12 Locations

There are 12 Ultimate Plans in Assassin's Creed Black Flag Resynced. Six are inside underwater diving locations, while the other six are buried treasures that require a matching treasure map. Each plan unlocks the final tier of a specific Jackdaw upgrade; you still have to pay the listed Reales and materials at a Harbormaster.

Quick answer: finish This Old Cove and fully upgrade the Great Inagua Harbormaster to install Ultimate upgrades. Complete Diving for Medicines to access the six underwater plans. For the six buried plans, collect the corresponding map before visiting the dig site.

All Ultimate Plan Locations and Costs

Coordinates are written as (X, Y). The “map → dig” rows require both steps; sailing directly to the dig coordinate without the map will not produce the dig prompt.

Ultimate Plan	Where to find it	Final upgrade cost	Priority
Hull Armor	San Ignacio wreck (348, 745)	30,000 Reales, 400 Metal, 750 Wood	Essential
Broadside Cannons Number	The Blue Hole (440, 145)	20,000 Reales, 650 Metal	Essential
Mortars	Antocha Wreck (600, 636)	25,000 Reales, 650 Metal	High
Round Shot Strength	Kabah Ruins (738, 120)	35,000 Reales	High
Ram	La Concepción Wreck (150, 271)	15,000 Reales, 200 Metal, 600 Wood	Medium
Swivel Guns	Devil's Eye Caverns (456, 332)	15,000 Reales, 400 Metal	Medium
Heavy Shot Strength	Ambergris Key (28, 159) → Misteriosa (271, 178)	25,000 Reales	High
Mortar Storage	Tortuga (847, 351) → Matanzas (312, 617)	5,000 Reales	Medium
Heavy Shot Storage	Cayman Sound (298, 311) → Petite Caverne (863, 235)	4,000 Reales	Medium
Fire Barrel Strength	Santanillas (189, 220) → San Juan (455, 462)	8,000 Reales	Situational
Fire Barrel Storage	Petite Caverne (862, 237) → Tulum (40, 372)	4,000 Reales	Situational
Harpoon Strength	Mariguana Island (47, 514) → Andreas Island (544, 693)	4,000 Reales	Hunting only

Six Diving Location Ultimate Plans

Buy the Diving Bell for 5,000 Reales and complete Sequence 6, Memory 1, Diving for Medicines. Secret plan chests are slightly larger than ordinary loot chests and count as each diving location's Secret.

Hull Armor — San Ignacio Wreck (348, 745)

San Ignacio is northeast of Havana in the Dry Tortuga region. From the diving bell, swim toward the large broken hull in the northwest part of the wreck site. The plan is in the large chest inside that hull. A shark patrols the approach, so use sea grass and fish schools instead of crossing open water.

Broadside Cannons Number — The Blue Hole (440, 145)

The Blue Hole is west of Kingston in the Charlotte region. Descend to the seabed and search the northern corner of the site. The Ultimate Plan chest rests against the edge of the underwater area, with a shark circling nearby.

Mortars — Antocha Wreck (600, 636)

Antocha Wreck lies northwest of Great Inagua in Gibara. Head for the southern corner of the wreck and enter the broken ship section containing the large plan chest. Keep cover between Edward and the shark while crossing the exposed gap.

Ram — La Concepción Wreck (150, 271)

La Concepción is southeast of Fort Chinchorro. The Ram plan is in the first large chest north of the diving bell, making it one of the shortest Ultimate Plan dives once the location is unlocked.

Round Shot Strength — Kabah Ruins (738, 120)

Kabah Ruins is east of Kingston in Navassa. Take the long, narrow tunnel running north and follow it to the end. The current starts and stops, so move into the side recesses when it pushes against you, then continue during each calm interval.

Swivel Guns — Devil's Eye Caverns (456, 332)

Devil's Eye Caverns is west of Cabo de Cruz. Follow the northern underwater passage until it opens into a dry chamber. The plan chest is in a dark corner on the left after Edward climbs out of the water.

Six Treasure Map Ultimate Plans

These plans use the normal buried-treasure rules: loot the map first, open it in the inventory if you want the illustrated clue, then travel to the second coordinate and look for the dig prompt. Our complete Treasure Map guide lists every map and reward in the game.

Heavy Shot Strength — Ambergris Key to Misteriosa

1. Collect the map in the upper section of the Ambergris Key smuggler den at (28, 159).
2. Travel to Misteriosa (271, 178).
3. Climb the Maya structure and dig beside the fountain at the top.

Mortar Storage — Tortuga to Matanzas

1. Collect the Tortuga map at (847, 351).
2. Travel to Matanzas (312, 617).
3. Find the waterfall southeast of the Mayan Stela and dig beside it.

Heavy Shot Storage — Cayman Sound to Petite Caverne

1. Loot the corpse beside the barrels on Cayman Sound's northwest beach at (298, 311).
2. Enter the Petite Caverne smuggler den at (863, 235).
3. Continue to its deepest section and dig near the rocks by the wooden bridge and campsite.

Fire Barrel Strength — Santanillas to San Juan

1. Pick up the map on the high eastern cliff at Santanillas (189, 220).
2. Sail to San Juan (455, 462) and enter the underwater tunnel.
3. Dig in the first dry chamber beside the old cart.

Fire Barrel Storage — Petite Caverne to Tulum

1. Find the map behind crates near the center of the Petite Caverne den at (862, 237).
2. Travel to Tulum (40, 372).
3. Search the southern beach near the watchtower and dig by the palm trees.

Harpoon Strength — Mariguana Island to Andreas Island

1. Collect the map at Mariguana Island (47, 514).
2. Travel to Andreas Island (544, 693).
3. Search the small patch of land on the southern beach and dig beside the lone palm.

Best Ultimate Plans to Get First

1. Hull Armor — the largest survivability gain and the safest first choice for forts, high-level Man-o-Wars, and Legendary Ships.
2. Broadside Cannons Number — improves the Jackdaw's most frequently used attack.
3. Mortars — strengthens long-range opening damage and makes fort approaches safer.
4. Heavy Shot Strength or Round Shot Strength — choose Heavy Shot for close-range aggression or Round Shot for a more flexible broadside build.
5. Ram and Swivel Guns — valuable after the core hull and cannon upgrades are finished.
6. Storage, Fire Barrel, and Harpoon plans — useful, but less urgent unless your build or current activity depends on them.

The plans only remove the blueprint gate. Check the full Jackdaw upgrade cost guide before farming Metal, Wood, and Reales.

Frequently Asked Questions

How many Ultimate Plans are in AC Black Flag Resynced?

There are 12: six in underwater diving locations and six obtained by solving treasure maps.

When can you collect Ultimate Plans?

Treasure-map plans can be collected as soon as their locations and maps are accessible. The six underwater plans require the Diving Bell and completion of Diving for Medicines. To install final upgrades, fully upgrade the Great Inagua Harbormaster after This Old Cove.

Do you need the treasure map before digging up an Ultimate Plan?

Yes. For the six buried plans, the dig prompt normally appears only after you collect the matching map. The six diving plans do not require maps.

Which Ultimate Plan should you get first?

Get Hull Armor first for survivability, then Broadside Cannons Number and Mortars for damage. This order gives the biggest benefit across ordinary naval combat, forts, and Legendary Ships.

Sources

• Polygon — all Ultimate Ship Plan locations and upgrade costs
• VGC — all Ultimate Plan ship upgrade locations
• Game8 — all Treasure Map locations and rewards

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Related: Jackdaw Upgrade Costs | Treasure Map Locations | Ships & Naval Combat | Legendary Ships | Collectibles Checklist