Card , i just want to ask you something. Do you put something in your ears ? Because i was at the pool yesterday and my ears blew up in 5 meters deep 
Or it doesnt matter because you got oxygene ? And you keep on breathing ?
Every time you breathe you toggle your nose with your hand and blow so the air pops out your ear drums again.
You keep doing that as you keep going down, when you reach the destination height you wanna stay at you just paddle straight and you won't have to do so over and over again.