The maximum depth in Tiny Fishing is 1215m, as shown in a YouTube video by user TinyFishingPro777 in 2021. However, it seems that there is no definitive end to the depth in the game, and reaching this depth does not yield any new content or rewards. The game appears to have an indefinite maximum depth, and beyond a certain point, the visuals and fish remain the same, with no increase in their value. Therefore, players may continue fishing for enjoyment, but there is no specific endpoint or additional content beyond 1215m.