How do the local authorities deal with these kinds of trips? Two countries on one trip – any hassle with bureaucracy?

The authorities of each country are getting used to this kind of trips, at the beginning (first two trips) the authorities in both countries were very strict as they were not used to this kind of trips & getting confused to treat the permission as diving trip or passenger ship doing a short international voyage between two countries with passengers. Then things are getting smoother & became more flexible, on each trip now we feel that the permissions procedures & time are getting shorter than before.