I have so much trouble with water in my ears that I have come to avoid swimming under water. But when I had a chance to do some tropical snorkeling, I couldn't pass it up and I ordered these and another type of ear plug. I had my doubts when I put these in, because I could still hear pretty well with them in but when I went into the water, they worked perfectly! I was careful to follow the instructions, which seemed to really help them seat in the ear canal. I noticed they sealed so well that I had to twist them to break the seal before pulling them out so the suction wouldn't hurt my ear. Had a wonderful time snorkeling for several days thanks to these! BTW, I never even tried the other plugs I bought.