Final answer:
Check by phone payments must be made within the cruise line's specified timeframe prior to departure to ensure processing. Onboard transactions are typically cashless, and guests settle them at the cruise's end.
Step-by-step explanation:
Check by phone payments for a cruise are usually subject to specific policies set by the cruise line, including restrictions on when they can be made.
These policies often require such payments to be completed well in advance of the departure date. The summary of onboard bills from the surveyed single travelers and couples for a seven-day cruise from Los Angeles to the Mexican Riviera, as mentioned, helps emphasize the point that most onboard transactions are handled in a cashless manner, with guests settling their bills at the end of their journey.
Since the survey pertains to onboard transactions rather than the payment method for the cruise itself, it's important to clarify that the cashless system is separate from the initial cruise payment. The timeframe for accepting check by phone payments will vary depending on the cruise line's policy, but it could be hypothesized that such payments need to be made well outside of a certain number of business days prior to the cruise to ensure processing time and avoid any potential payment issues as the departure date approaches.