This answer very much depends on the primary reason for the travel. As a general rule of thumb, don't write off an expense unless you can prove it relates to work.
Is this in-person marketing necessary to your business and the main purpose of traveling to an island? Or do you want to spend the winter on an island, and are taking advantage of the location to do some business marketing while you are there?
Deductions for business travel can be available when someone must travel away from their tax home or main place of work for business reasons.
Trips that are primarily for personal reasons or vacations are completely nondeductible. However, if you do conduct any business while you are at your destination, only expenses that are 100% directly related to your business are deductible. For instance, supplies, internet access, possibly mileage from where you are staying to a business meeting if the business is the primary event (but not if you are doing personal golfing and will happen to hand out some business cards while you are there.)
Additionally, there are specific rules relating to business travel outside of the United States. If you travel outside the United States primarily for business but spend some of your time on other activities, you generally can’t deduct all of your travel expenses. You can only deduct the business portion of your cost of getting to and from your destination. You must allocate the costs between your business and other activities to determine your deductible amount.
If you do decide to deduct expenses for this travel, you will need to keep meticulous records. You should keep all receipts, invoices, etc. Keep logs for time, mileage, and client contacts. Be prepared to substantiate how many hours you spent on business vs pleasure.
Review IRS publication 463 carefully, especially the section 'Travel Outside the United States' to see which allocations apply to your situation.
