This, unless my sinuses are somewhat clogged. If so, I do the Valsalva.Maybe what I do is close to the VTO, though I don't push my jaw forward. I just open my Eustachian tubes somehow--like when yawning, but I don't have to yawn. I just make my ears "crackle". I can hold the "crackle" position at will and do this on land if something really noisey approaches (like a fire truck while I'm walking)--so I don't plug my ears with my fingers looking like a dork. If I'm going down real fast I do occasionally swallow now and then.