Well you have to use the diving bell to get into the smugglers den, when you get into the cave there is a ladder you can climb that will bring you back to your ship. Right at the base of the ladder, to the left, is where the chest spawns. Now it didn't show for me right away, in fact I walked around for several minutes waiting for it to appear and it wouldn't. By chance, I had a space heater plugged in that flipped a circuit breaker and shut off my xbox. When I got it back on, I was right at the dive sight again. Went back to den, and when I got there, saw the notification pop up that I found the chest, and there it was. Now I've heard that resetting/revisiting an area multiple times will make the events spawn. Not sure if it had anything to do with it. Also earlier today I cleared my cache. Not sure if that matters, but I heard a rumor that it does. I've been searching for these things for so long now I was willing to try anything. Again not sure if any of these things matter, but that was the exact process that got me the chest. I hope this helps.
That's weird. It just straight-up didn't show for me. Spent about 10 minutes just walking around.
Try resetting and revisiting. The rumor is that these events are server specific, and you need to be on the correct server to see them. Although there was one reported by several people yesterday at grand cayman, and none of the "tricks" worked for me.
To the person who didn't find it, welcome to my world! People finding them, friends on my list, and it not being shared, and it not being there for me, I look over and over, by resetting my xbox, unplugging it to truly turn it off, then sail to the location, not quick travel like 5 times and not there for me. THe game is so messed up. I don know how it hasn't been patched. DO you know the master list? anytime someone finds a chest, give the coordinates, or the island, and this master list just find the corresponding chest and this table couldn't make getting to tit any easier.
SHows pictures of the chest location, the coords, everything. even where to look if your searching, al possible spawn locations known.