All ports are different and some ports require a face to face Immigration Inspection. These will either be conducted on board the ship or ashore, details of this will be provided once you are on board and are subject to operational requirements.
When transferring between two ships on the same day, there will be a transfer for both guests and their luggage. The transhipping guests must be disembarking/embarking on the same date. The transfers will be organised by the ships and you will be notified on board if this transfer is possible and all further details regarding this.
US Ports.
All guests must disembark regardless of Nationality and whether they are in-transit or not, to pass through the Immigration and Customs Inspection with CBP (Customs and Border Protection). CBP relates to US cruises only.
The zero count requiring everyone to disembark is a CBP requirement.