"Sore wa mizu desu ka"
My Japanese is sketchy at best, but I think that's about right. Honestly, as long as you get at least a few of the right words in there somewhere, they'll be able to understand the basic question you're asking. It's kind of like someone talking you you in broken english: it's not perfect, but you can usually understand what they are asking.
Other things that might be useful: (translations aren't completely accurate I'm sure, but it's close.)
Konnichiwa= basically hello. Kon-ni-chi-wa
followed by
Ogenkidesuka= how are you Oh-gan-ki-dess-ka (the way I was taught, the "oo" sound is silent or very rushed) The probable answer will be "hai, genkidesu" which is along the lines of "I am doing well"
Do you understand= wakarimasuka wa-cari-masska (with a curious tone)
them: hai, wakarimasu (yes, I undersand) iie, wakarimasen. (no, I do not understand)
arigato ari-gaa-toe= thank you
domo arigato gozaimasu do-mo ari-gaa-toe go-zai-mass = more formal way of saying thank you.
ooh...this isn't close to all of the things you want, but it's got a few phrases that might be useful.
http://www.ida.net/users/aikido/Clas...n-phrases.html