Updated Title Publisher
Updated Title Publisher
Updated Title
Published Title Score Editor's Choice Publisher
Published Title Publisher

Edward Kenway is a pirate first and foremost, and as such the quality of his ship is paramount - no amount of stealth, swordplay or marksmanship is going to substitute for upgrading the Jackdaw when a hostile man o’ war appears on the horizon. While the base Jackdaw may be able to fend off cutters, sloops and brigs, you’ll eventually start running afoul of more potent ships, and you’ll need to invest in the Jackdaw. To maximize your odds - especially if you care to deal with endgame content like Legendary Ships and the more difficult Forts - you’ll want to seek out the most powerful ship upgrades. This page will provide some info on these upgrades and all their locations in Assassin’s Creed Black Flag Resynced.

Page Breakdown

Upgrading the Jackdaw is necessary to survive in the southern Caribbean and challenge the most difficult endgame content!

Upgrading the Jackdaw

To upgrade the Jackdaw, you’ll need to visit a harbourmaster at various settlements and purchase them. They tend to cost reales in addition to cloth, metal and wood - resources you can obtain in abundance by plundering other vessels. This is a slow, expensive but necessary process, but in many cases the final upgrade also requires you to obtain an ultimate upgrade plan. A list of every ultimate upgrade plan and their locations can be found on the table below:

All Ultimate Ship Upgrade Plan Locations

Ultimate Upgrade Plan Location Requirements
Round Shot Strength Upgrade Plan Sunken Chest in the Kabah Ruins Complete Diving for Medicine
Heavy Shot Strength Upgrade Plan Buried Treasure in Misteriosa Ambergris Key treasure map
Fire Barrel Strength Upgrade Plan Buried Treasure in San Juan Santanillas treasure map
Mortars Upgrade Plan Sunken Chest in the Antocha Wreck Complete Diving for Medicine
Swivel Guns Upgrade Plan Sunken Chest in the Devil’s Eye Caverns Complete Diving for Medicine
Broadside Cannons Upgrade Plan Sunken Chest in the The Blue Hole Complete Diving for Medicine
Ram Upgrade Plan Sunken Chest in the La Concepcion Wreck Complete Diving for Medicine
Hull Armor Upgrade Plan Sunken Chest in the San Ignacio Wreck Complete Diving for Medicine
Heavy Shot Storage Upgrade Plan Buried Treasure in Petite Caverne Cayman Sound treasure map
Fire Barrel Storage Upgrade Plan Buried Treasure on Tulum Petite Caverne treasure map
Mortar Storage Upgrade Plan Buried Treasure in Matanzas Tortuga treasure map
Harpoon Strength Upgrade Plan Buried Treasure on Andreas Island Mariguana Island treasure map

Ultimate Upgrade Plan Requirements

Purchasing the various categories of ship upgrades generally fall into three categories: Upgrades whose upgrade plans are found as buried treasure, upgrades whose upgrade plans that can be found in shipwrecks, and upgrades that do not require and ultimate upgrades that do not require ultimate upgrade plans. Obviously you don’t need to worry about the latter, so we’ll discuss the buried treasures and shipwrecks.

(1 of 3) Sometimes you’ll have to scour points of interest for treasure maps,

The buried treasure upgrade plans require you to explore the Caribbean thoroughly, land at points of interest, and find the treasure map there. These are listed as “Secrets” when viewing an area, but appear as scrolls when you zoom in. If you can’t find the scroll icon marking these treasure maps, synchronise at viewpoints and explore and they should show up. Once you have the treasure map, go to the location of the ultimate upgrade plan (see the list above) and use the map to find the exact location of the buried treasure. Aside from Kenway mumbling about the buried treasure being close, there aren’t any other markers or indicators to help you until you’re right on top of the treasure, at which point you’ll get a prompt to dig it up. Check out the map links provided to find the location of the buried treasure you seek.

After you get the Diving Bell, seek out marked dive spots on the map,

and search these dive spots for submerged treasure, which can sometimes yield ultimate upgrade plans!

Shipwrecks are a bit of a bother - while you can technically explore most of the map after completing the main quest This Old Cove, you must complete the main quest Diving for Medicine before you can get any of the ultimate upgrade plans sunken in chests along with the ship they were on. Once you have the Diving Bell, however, you can search for shipwrecks (a generic term used for what more accurately should be called diving spots) and dive at them. You’ll have to manage your oxygen, using oxygen barrels to recover expended O2 while also dodging sharks, urchins and jellyfish as you search for these chests. Remember that you can hold down DualSense-L2 to spot these chests as you explore - they’ll appear as glowing white dots… or you can just use the provided map again to pinpoint their locations.

Once you get an ultimate upgrade plan, you’re pretty much done - it’s just a component you need to have on-hand when you purchase the upgrade from a harbourmaster. Just pull it out a chest and you’re golden!

Written by
Nathan Garvin

Nathan has been working at Gamer Guides since 2014 where he started as a contributor. He came on as an editor in 2020 where he continues to put his excellent knowledge of most things RPG to use. More about Nathan Garvin

No Comments
No Upvotes
User profile pic

Comment submission error:

The comment must be at least 1 character in length.

Guide Information
  • Platforms
    PC, PS5, XB X|S
  • Guide Release
    7 July 2026
  • Last Updated
    31 July 2026
    Version History
  • Guide Author

Share this free guide:

Facebook X Bluesky

Assassin’s Creed: Black Flag Resynced is a remake of the 2013 game in the series, Black Flag, which was the fourth main entry. While the game retains the majority of the major plot points of the original, it offers some new content in the form of quests, reworked stealth and combat, and a lot more changes. Unlike recent entries that leaned toward the RPG side of things, Black Flag Resynced is still the same type of action-adventure as before. This guide contains the following content:

Pencil icon Sign up

Or

Gamer Guides Premium


Find out more

Receive email updates with the latest content - 100% free!

New Maps
New Databases
New Guides and much more…

You can unsubscribe at any time.

GG logo

Register to continue…

Already have an account?

Log in to continue…

Forgot?

Don’t have an account?


Account Created

Select username: