Location 10
You can find it by the crane at the Main Dock.
Underwater Locations
There are 9 possible underwater locations.
Location 1
You can find this chest underwater by the north drop zone. The chest will be next to a big boulder.
Location 2
This one is found underwater at the end of the runway. But not the western end. You need to go underwater but in the northern direction. The chest will be next to a rock, as highlighted in the image below.
Location 3
This chest is found in the underwater section between the control tower and the power station. The chest will be in a small open area surrounded by underwater grass or weed.
Location 4
This location is directly south of the power plant and solar panel farm. The chest will be next to a huge boulder. It might be a bit difficult to find it as there's a lot of overgrown weed here.
Location 5
This underwater location is just behind the large hangar, which is located by the runway. You will find the chest in the marked location, as shown in the image below. It is quite difficult to pinpoint these chests' exact location when underwater, the best way to find this one is to look for a huge orange-colored spore/mushroom. The chest will be next to it.
Location 6
This location is just by the main security checkpoint leading you into the main operational island area. The underwater location is slightly northeast of the checkpoint. You will find the chest quite easily as it is an open underwater area with a meager number of underwater plants. The chest is also out in the open and not in the plants. It is easier to spot.
Location 7
This is in the far southeastern section of the island where the lighthouse is located. For this particular location, swim by the purple spores shown in the image below. You will find the chest in a huge patch of overgrown weed and other plants. Swim around the location, and you will eventually get a prompt to collect the treasure.
Location 8
This chest location is probably the easiest to find. You will find this chest underwater under the wooden dock pathway at the Main Dock.
Location 9
The last underwater location is far west of the island, just outside El Rubio's compound boundary. You will find three large spores. Two of them will be dark, and one will be in a light orange color. Approach the orange one, and you should get a prompt to collect the chest. The chest is somewhere in the overgrown weed next to the orange spore.
