I thought it was. I find my Chota mukluks are waterproof for a few minutes. If I stand in the water longer than a few minutes, I start to feel a minute amount of water seeping through.
Is it coming through a hole or a seam, or does it seep through the neoprene itself with longer immersion?
Boots are a few years old. I never noticed this problem before, but I never stood in the water for very long until recently.