already has experience to get comfortable with going from a normal scuba mask and a separate regulator in your mouth to having everything combined into one and then add that component, the communications feature which is a wonderful feature to have in the masks. but the training curve, you know, for a teen that has -- or the adult that's never been on scuba to begin with and suddenly throwing them into something we don't begin to train with much before 30, 40, 50 hours worth of dive experiences as a emergency services diver. it's a big learning curve. it's a very fast one. obviously, the first four have taken to that challenge quite nicely. >> you know, cave diving for exploration or as an adrenaline sport that, is challenging enough. it has special challenges which you already outlined. but when you mix a rescue into it, i mean, how much different does that make the calculus?