visa

Thank you for informing me that as a British citizen I do not need a visa to enter Vietnam.
I would also like to know, if, when I return to the cruise ship, which I am expecting to do on at least 6 occasions when I shall be visiting 3 ports, I will still not need a visa to return to shore.
I wondered if I am leaving the country by going back on board, and therefore unsure if the phrase “the previous visit must be far at least 30 days the next visit.” applies to cruise passengers.
Regards,
Janet