There are multiple definitions - click on the translation that matches your context.

改变船舶登记国

动词

full

reflag

verb

Definitions of reflag

to present or market something differently to the way in which it was originally presented or marketed

The Company plans to renovate the hotel and reflag it as a Hawthorn Suites.

to register a ship in a different country and therefore give it the right to fly a different flag

"The Pride of Hawaii" has been reflagged and renamed "Norwegian Jade".