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.
Celebrity Cruises was founded in April 1988 as a subsidiary of the Greece-based Chandris Group to operate upmarket cruise ships to Bermuda. Chandris had been involved in cruise traffic since the 1960s, and during the late 1980s the company operated in the United States market under the brand name Chandris Cruises.