I found out about this last week. I emailed the embassy and this morning received an email detailing the visa process. However, no specifics regarding whether this is required for cruises. One of the requirements in the process is to give details of the hotel for overnight accommodation. The ship won’t overnight, so I have replied asking for clarity on cruises.
I also contacted Princess and was told, in writing, that they won’t allow us on board without required visas. This is in case of any emergency requiring debarkation in a country with visa requirements.
i will be holding my breath for updates from here and will update myself if I hear back from the embassy.