Echoes In Eternity Quest Guide
Echoes in Eternity is a Side Quest that you get while doing the Out of Our League mission in Blue Mountains. It can be found towards the end of the last tier and invovles you following a tracker to a few different places to complete the quest. The first of which is a boat south of your location. It's fairly easy to find and the guy's corpse you need to search; it is hanging off of the front balcony. After that you move onto tier 2 where you need to find the soldier a little bit south of where you are. He is sitting up against the side of the cliff leading up to land from the beach.
Once you find him you'll have to collect his dog tags which brings us to the reason I made this guide. The dog tags drop from the Cold Seep Threasher which spawns in one of two different locations on the beach. The very first is in the first screenshot below and is right across from the corpse on a little island guarded by two oracles.
The second spawn location is up north closer to the boat by a large rock wall facing the ocean. The large rock wall raises the little "platform" they're standing on above ground. I have a picture of it in the screenshot below. If you're having trouble seeing with this picture just click to enlarge it. Keep that in mind for future small pictures on my website!
After killing the Cold Seep Threasher for the dog tags you will want to continue onto Tier 3. This dead soldier is a little bit harder to find since you can't actually find him until you attack the Drowned Mariner eating his corpse. You must engage the Drowned Mariner in order to get credit for finding the corpse. Below is the last part of the guide which is a screenshot of where you can find the Drowned Mariner!