You can deduct your travel expenses when you attend a convention--if you can show that your attendance benefits your business. Note: You cannot deduct the travel expenses of your family. The convention or seminar must have scheduled a minimum of six hours during the day (and that you attend at least two-thirds of those activities--more than four hours).
You can also deduct up to $2,000 each year for attending cruise ship conventions that are directly related to your business. To do this, you must meet all of the following conditions:
- The ship must be registered in the United States.
- All ports must be in the United States or one of its possessions.
- You must submit two supporting statements with your tax return.
- You must spend at least 51 percent of your (waking) time attending the seminar.
Source: Travel-Related Tax Deductions