Pneumousia Relay Puzzle in Elton Trench

An underwater dome locked by Pneumousia Relay puzzle is keeping a Precious Chest and a Hydroculus inside it. Here’s how to solve the puzzle and obtain both items including a hidden achievement ‘These Are a Few of My…’

How to unlock the Underwater Dome in Elton Trench

➥ Teleport to Elton Trench underwater waypoint (just above the writing) and swim southwest to the dome. You can see a Blubberbeast and an Echoing Conch in front of the dome, and you can use that Echoing Conch to highlight the location of Pneumousia Blocks near the location.

➥ The Pneuma Block is not hidden at all and you can see it just beside the dome. Take the Pneuma Block and attack the Ousia Relay.

➥ The Ousia Block is also beside the dome but on the other side and on top of the huge leaf. Take the block and attack the Pneuma Relay.

➥ If the dome is still not unlocked after you turn both Relays to Neutral state, re-enter the game to refresh and the barrier will turn to blue (indicating that you can now enter it). This happens to me and re-enter solves the issue.

➥ Aside from the Precious Chest and the Hydroculus, face to the right and you will see a Gramophone with the option to play it. Choose Play to get the hidden achievement ‘These Are a Few of My…’