what does aqua affinity do

Aqua Affinity is a helmet enchantment in Minecraft that increases the speed of mining blocks underwater. It removes the penalty for mining underwater, which usually takes five times as long for the item to be broken. With Aqua Affinity applied, mining speed underwater becomes as much as mining speed on land, and all the mining penalties applied by the game are automatically ignored. This enchantment can be applied to any helmet, including a turtle shell, and it is not a treasure enchantment, so it can be obtained using books, enchanting tables, and even chest loot. Aqua Affinity will only affect the mining speed underwater and will not allow the player to stay underwater for longer periods of time. For that, the player needs the Respiration enchantment.