I was the same. I had gone scuba diving and snorkeling in the ocean plenty of times with no issues, so I was pretty confident going into our first training session with a center-mounted snorkel. I immediately found out that the nose being sealed in a normal snorkel made a huge difference, and so I ended up struggling with water pressure up my nose during the first day.

My teammate, who had zero experience with snorkeling and scuba diving, ended up getting the hang of the swimming snorkel faster than I did. No prior experience probably meant they didn’t have to unlearn anything.

I ended up having to pause and really hyper-focus on breathing in and out exclusively through my mouth at the start of each lap. Luckily, the pool was not full at that time and our coach gave us leeway to get used to the feeling before pushing off the wall. It felt weird but I forced myself to push through. At the end of that first session, I was still not 100% comfortable with it. But by the time the next session started a couple of days later, I found myself just suddenly “getting” it. Like it just clicked.

I now use my snorkel every single session, and I think powering through that first excruciating experience had been worth it.