Per the IRS.......Yes, however, if you travel by ocean liner, cruise ship, or other form of luxury water transportation for business purposes, there is a daily limit on the amount you can deduct. The limit is twice the highest federal per diem rate allowable at the time of your travel. (Generally, the federal per diem is the amount paid to federal government employees for daily living expenses when they travel away from home within the United States for business purposes.)
Meals and entertainment. If your expenses for luxury water travel include separately stated amounts for meals or entertainment, those amounts are subject to the 50% limit on meals and entertainment before you apply the daily limit.
If the convention is for investment, political, social, or other purposes unrelated to your trade or business, you can’t deduct the expenses.
You can deduct up to $2,000 per year of your expenses of attending conventions, seminars, or similar meetings held on cruise ships. All ships that sail are considered cruise ships.
You can deduct these expenses only if all of the following requirements are met.
The convention, seminar, or meeting is directly related to your trade or business.
The cruise ship is a vessel registered in the United States.
All of the cruise ship's ports of call are in the United States or in possessions of the United States.
You attach to your return a written statement signed by you that includes information about:
The total days of the trip (not including the days of transportation to and from the cruise ship port),
The number of hours each day that you devoted to scheduled business activities, and
A program of the scheduled business activities of the meeting.
You attach to your return a written statement signed by an officer of the organization or group sponsoring the meeting that includes:
A schedule of the business activities of each day of the meeting, and
The number of hours you attended the scheduled business activities.
You can’t deduct expenses for attending a convention, seminar, or similar meeting held outside the North American area unless:
The meeting is directly related to your trade or business, and
It is reasonable to hold the meeting outside the North American area. See Reasonableness test , later.
If the meeting meets these requirements, you also must satisfy the rules for deducting expenses for business trips in general, discussed earlier under Travel Outside the United States .
[Edited 2/24/2017|11:14am]