Elite Heavy Shot, Misteriosa Island
Coordinates – 307,195
You’ll need the diving bell to reach the map at Ambergris Key which is on the second floor of the structure. The Heavy Shot upgrade itself is on the highest structure on Misteriosa Island. Climb to the top and look to the left of the water fountain.
Elite Hull Armor, San Ignacio
Coordinates – 379,770
Look for the wreck near some bright green seaweed. There’s a lot of sharks here but at least the wreck is fairly open meaning you don’t have to worry about getting in. If you haven’t already collected it you should see a bright animus fragment as you approach. Collect that then hang a left to find the chest and the plans.
Elite Round Shot Strength, Kabah Ruins
Coordinates – 769,145
As soon as you leave the diving bell you should see a wreck with some ruins to the right. Head to the front of the structure and you should find a door. The chest will be inside on the lower floor at the back. There’s a shark but if you’re quick it shouldn’t give you too much trouble.
Elite Mortars, Antocha
Coordinates - 630,660
You’ll need some nerves here as not only is there a shark to worry about but you’ll have to swim quite deep into the wreck. Look out for the weeds to avoid the shark and then head around to the hull break on the right (if you’re approaching from the stern). Swim inside and follow the passage around until you reach the cannon deck. Look out for a skeleton chained to the wall to on the right to locate the chest.
Elite Swivel Guns, Devil’s Eye Caverns
Coordinates – 488,353
Once in the Devil’s Eye Caverns look for that ‘V’ in the rocks and follow the tunnel you find underneath around to the left. If it’s full of jellyfish you’re going the right way. Stick to the left and you should eventually come into a small cavern with two chests. The one on the left has the Elite Swivel Gun plans.
Elite Fire Barrels, San Juan
Coordinate – 479,487
The map for this is found at the Northeast corner of Santanillas. You’ll then need the diving bell to locate the Fire Barrel plans in the Smuggler’s Den. Look for some broken planks on the wall to find where you need to dig.