My son has worn a CPAP mask for years, and it looks as if it would be difficult to get a drink of water with it on.

I forgot to mention that I also use a toothpaste for dry mouth put out by Biotene, as Debbie D already mentioned.

I brush with this 3 times a day.

If I sound like a fanatic, I am. I'm very determined to avoid going to a dentist. And my mouth can get so dry that I choke.

I carry around some (sugar-free) hard candy. One of those will take care of dry mouth problems that come up in places where water isn't handy.