What? Please explain more. What work did you do while on a cruise? For who? Was this your family's boat?
Good questions. I'm an independent consultant (IT) and the cruise was from Miami to Europe. One of my clients experienced an emergency and needed assistance resolving it. I feel somewhat deprived of my personal time, but satisfied I helped.
Thank you
Don't think you can expense any of it. You didn't go on the cruise FOR business. It wasn't a business trip. You can expense any supplies you used or phone calls, maybe some internet fees.
You may deduct all business expenses that are ordinary and necessary.
For the Meaning of Ordinary and Necessary Expenses, see: http://www.cpa-connecticut.com/ordinary-and-necessary.html