EVERSPACE 2

After the first time you get eaten by the leviathan and return to the BRI leviathan studies you will now be able to freely go back to Chenat when sittings appear.

Pearls are obtained by progressing far enough into the leviathan they give nice rewards when returned to the BRI base.

During the side quest it explains great on how sittings and how agitation works, but here's a quick rundown for this achievement.

Agitation is slowly increasing over time while inside the leviathan and increases when shooting or ramming different parts of the leviathan. When you complete the side objective to progress agitation will go down by 10-25% depending on objective, So if your fast enough or objectives are easy to clear this isn't to difficult.

But alternatively there is a uncommon consumable you can craft called a Musk Ejector lowers agitation when used while inside the leviathan by 15%, also a good tool when some objectives take awhile.
When you get to the last room with the pearl I've noticed the agitation does not increase, so freely use them before you grab the pearl.

Achievement pops when the pearl goes into your inventory.

When you get to the Pearl and Agitation is high use Musk Ejector to lower it below 20%.