A: Trips given as rewards to customers or salespeople are 100% tax deductible to the corporation. This rule applies regardless of whether the trip is a cruise, whether the destination is foreign or whether the ship is foreign-registered. The only exception is the limitation on "lavish or extravagant gifts," which is a subjective term that is defined by comparing the reward to the customer's achievement, not to the type of cruise per se. A $5,000 cruise for a customer would not be.

Source: Travel Weekly