1) If one immerses his hands in the water of a Mikveh (ritual purification pool) or in the water of a spring, this functions in place of washing one’s hands. Nevertheless, in this case, the Berachah is “Al Netilas Yadayim” and not “Al Tevilas Yadayim”. (Shulchan Aruch and Mishne Berura 159)
2) If one immerses one’s hands in water which is unfit for washing one’s hands but is fit for immersing, (for example sea water or water from the hot springs of Teveryah (Tiberias) which are unfit for washing because they are too salty or bitter), there are those who say that the correct Beracha is “Al Netilas Yadayim” (Shulchan Aruch 159, Ben Ish Chai and Kaf HaChaim), and others say that in this case one should say “Al Tevilas Yadayim”. (Rema ibid, Mishne Berura)
