Master the high seas with our complete guide to finding every Ultimate Plan in Skull and Bones. Learn how to upgrade the Jackdaw to Level 5, locate hidden blueprints through diving and treasure maps, and discover the best strategies to defeat legendary ships for exclusive cosmetic rewards.
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To become the most feared pirate in the Indian Ocean, you need more than just a sturdy hull; you need a ship upgraded to its absolute limit. Reaching Ship Level 5 requires finding specific “Ultimate Plans” scattered across the map. This guide breaks down every location and strategy you need to dominate the endgame.
1. Unlocking the “Big Three” Weapons
Before hunting for upgrades, you need the right tools for the job. Three essential weapons can be acquired for free by completing specific activities:
- Front Cannons (Double Shot): Captured by defeating the fort in the Dry Tortuga region (top left of the map). This provides massive forward-facing firepower.
- Rear Shrapnel Barrels: Obtained by capturing Fort Charlotte in the far south. These are perfect for slowing down pursuers and shredding sails.
- Deadman’s Cohort Mortar: An end-game auxiliary weapon unlocked through the main story quest “Everything is Permitted.” This weapon is vital for taking down massive Man-o’-War ships.
2. Core Ship Upgrade Locations (Ultimate Plans)
To hit Level 5, you must visit various diving sites. Here is where to find the essential blueprints:
Armoured Hull V
- Location: San Ignacio Wreck (Dry Tortuga Region).
- Benefit: Boosts your Armor to 5,000, making you significantly more resilient in battle.
Round and Heated Shot V
- Location: Kabah Ruins (Navassa Region).
- The Puzzle: You must navigate an underwater tunnel guarded by jellyfish to find the air pocket. Wait for the tide vibrations to pass before rushing to the treasure chest.
Broadsides Cannons VI
- Location: The Blue Hole (near Fort Charlotte).
- Tip: Look for the chest in the northern section of the Blue Hole. Keep an eye out for the giant sperm whale swimming above for a spectacular view!
Specialized Systems
- Mortar Ultimate Plan: Located at the Antocha Wreck (Gibara region). Watch out for sharks guarding the southern wreckage.
- Swivel Guns Ultimate Plan: Found in the Devil’s Eye Caverns. This involves a long underwater swim through a cavern system that eventually leads to a dry tunnel containing the chest.
- Ram Ultimate Plan: Located at La Concepcion Wreck. This is one of the easiest to find, sitting directly ahead of the diving bell.
3. The Treasure Map Hunt: Harpoons and Storage
Some of the best upgrades are hidden behind treasure maps. You must first find the map on a skeleton and then dig up the loot at a secondary location.
- Harpoon Strength: Find the map at Mariguana Island (skeleton in a cave) and dig it up at Andreas Island.
- Fire Barrel Strength: Find the map at Santanillas (atop the rocks) and dig it up in the hidden sea caves of San Juan.
- Heavy Shot Storage: Find the map at Cayman Sound and dig it up behind the massive waterfall in Petite Caverne.
4. Defeating Legendary Ships
Once your ship is fully upgraded, it’s time to test your mettle against the four legendary encounters. Each offers unique ship skins, wheels, and figureheads.
El Impuloto (The Rammer)
- Location: North-west (Dry Tortuga).
- Strategy: This ship focuses on ramming. Use rear fire barrels to punish its aggression or trail it at a 30-degree angle to avoid its broadsides while dealing your own.
- Reward: The El Impuloto Figurehead, Sails, and Hull.
HMS Prince (The Ghost Ship)
- Location: South-east (Navassa).
- Strategy: It hides in a thick fog and is immune to swivel gun criticals on its sides. Focus all fire on its front and back. Use chain shots to limit its mobility.
- Reward: The Grim Reaper Figurehead and a stunning black and gold hull.
The Twin Ships: HMS Fearless & Royal Sovereign
- Location: North-east (Eleuthera).
- Strategy: Do not sail between them, or they will double-broadside you. Use one ship as a physical shield against the other. Once one sinks, the other becomes enraged and will try to ram you.
- Reward: The “Lion with a Crown” Figurehead and the HMS Fearless Hull.
Conclusion
Upgrading your ship to Level 5 is a journey that takes you from the deepest diving wrecks to the most dangerous forts. By following these locations and mastering the legendary battles, you won’t just survive the Golden Age of Piracy—you will rule it.
