Surely you had cases when you had to dive quite deep into Minecraft, and it happened that there was not enough air. Now this problem can be solved once and for all, this mod will add scuba gear to the game, which you can use to immerse yourself in water.
Mod Simple Diving Gear for Minecraft 1.15/1.14.4
Create a costume with air balloons, put on a special helmet and start exploring the underwater depths!
1.15 – Simple-Diving-Gear-Mod-1.15
1.14.4 – Simple-Diving-Gear-Mod-1.14.4