Plain coconut water is literally just the water on the inside of a coconut. So if you can get coconuts at your grocery store you can get coconut water. I also found this recipe on how to extract and flavor the water: http://www.eatnapplay.net/2013/03/04/make-your-own-coconut-water/.
About Celebrity Solstice. Celebrity Solstice is a large ship, carrying 2850 passengers and 1246 crew, and sails from Sydney, Australia and Auckland, New Zealand.
The Celebrity Infinity joined the Celebrity Cruises' fleet in 2001, and was significantly renovated in 2011, when new AquaClass staterooms, new dining venues, and new lounges were added. The Infinity is a sister ship to the Celebrity Millennium, Summit, and Constellation, which have also been renovated.