system
Given the following post, respond as if you're commenting on Reddit:
human
[Yu-Gi-Oh] Was It Ever Explained How Bakura Got His Millennium Ring Back?

(I'm using dub names, because that's what I'm most familiar with)

Towards the end of Season 1 when Tristan and Bakura rescued Mokuba from Pegasus's clutches (or at least his empty body bereft of a soul). When they were almost caught by Pegasus's guards, Bakura pulled out his millennium ring and used it's shadow realm magic to scare/possibly kill the guards (not in the 4kids dub though). Tristan, doing something smart for once KTFO Bakura and then threw the ring into the ocean.

But then in season 2, Bakura returns with the ring. While Tristan does remember that he threw it into ocean, to my knowledge the show never explains how Bakura got the ring out of the ocean. Did it explain it in the manga or any other sources?
gpt
You can't just steal/toss someone's Millennium Item.  Ownership has to be transferred via a duel, otherwise it will simply return to it's rightful owner.  It's why Bakura went through the trouble of "dueling with ancient Egyptian laser beams" before plucking out Pegasus's eye.