yes, the rougher/deeper the water, the better swimmer you need to be.
the vests they give you at CC inflate (you blow them up) in an emergency, not meant to be inflated while snorkeling.
To really see much of anything while snorkeling at CC, you have to go a ways out (i.e., it gets deeper).
My snorkeling excursion in ST Thms was cancelled due to rough waters in Nov. I was disappointed, but I know that my twin 7 year olds wouldn't have lasted long - not being strong swimmers, they would've tuckered out quickly and we'd probably spend the bulk of the excursion on the boat or beach.
As an aside, I had bought cheap mask/snorkel at
Walmart for the kids to practice in the pool, to get comfortable with the gear.
just keep swimmin', just keep swimmin'...
