Tumble turns with snorkel

I spent some time today trying to teach myself to tumble turn with a snorkel. I can tumble turn fine. I can swim with a snorkel fine. When I try to put the two together, I repeatedly half-drown (and frustrate) myself. Tips?
  • At a swim meet last night one of the coaches was talking about the AMEO Powerbreather Sport Snorkel. It costs significantly more than regular swim snorkels, but it sounds like the Powerbreather may have a solution to the water in the pipe issue. I haven’t tried one, or even seen one in action. But it looks like an interesting swim toy.
  • The AMEO Powerbreather snorkels work very well indeed, and are excellent training devices. But be forewarned: snorkels are specifically mentioned in USMS rules 303.7.2D and 303.7.3C as illegal for racing in USMS-sanctioned open water swims, "...except in designated events where all swimmers may use similar devices."