I use a CPAP machine and I just used the ships tap water. I did not see that just 7 days of their water hurt it in any way. But if you can bring your own water then you won't have to worry about it. We also took a power strip because we was worried about the plug in situation. Our stateroom attendent gave us an extension cord to plug my machine into, so everything worked out just great!
10-14-07 Freedom of the Seas
10-04-08 Liberty of the Seas