My issue is probably related to a ruptured eardrum I experienced in my 20's. I was swinging on a rope swing out over the water, and I landed badly from a height of about 15 feet with the left side of my head flat to the surface. That ear has never been right since, and that eustachian tube sometimes gets blocked for days at a time. On a dive vacation it gets harder and harder to clear that ear every day, and it has given me a couple of scares at depth even when I have taken pseudoephedrine for every dive. If I have to choose between running out of air and coming up with a reverse squeeze, that's not a good place to be.It seems to be there is a pretty large percentage of divers who have some sort of ear issues. Always someone on the boat talking about bad or slow ears.
This year I went to an ENT and got his recommendations for my trip later in May.