Alain, I hope I didn't sound bombastic about Bombard. His effort was a very big step, or paddle forward in marine survival. I am sure a good percentile of our contemporary knowledge and gear will come under future criticism. Pete, thanks for hydrating my dessicated answer. My lecture was a long,long time ago and the class was taught by a CPO less than articulate. He finally just bellowed " Drink seawater and you will be court-martialled" easilly remembered after cellular osmosis was long forgotten <img src="/images/graemlins/grin.gif" alt="" />