Instant Air Replenish

Starting from Minecraft version 1.13 and later, player oxygen regenerates gradually after leaving water, rather than instantly as it was before.

This mod restores the functionality that existed prior to version 1.13 using the game rule 'toggleOldAirReplenish'. This rule is enabled by default (true), and server administrators can change it using the following command:

/gamerule toggleOldAirReplenish true/false