Arrivals - Flag protocol
Flag communication is a relic of the past but it is still very much in use today. Whislt some countries are lax about the protocols, others take the issue very serious and you might even get into hotwater for not following the correct flag procedures. Besides this, it is part of our heritage and this is also the correct international accepted flag procedure when arriving in a host country. The yellow (quarantine) flag must be raised in your vessel is in territorial waters and if you intend making landfall. There is no need to fly the yellow flag if you are simply passing through the territorial waters and not make landfall.
As a visitor in the host country, it is good courtesy to fly the host country's national flag - make sure that it is in a higher position than your own country. In addition, some officials will be quite upset if the host country flag is smaller than you own flag! Although many of the requirements are not always strictly enforced.
This Acrobat Reader file graphically shows you the flag protocol, how and where to fly your flags when arriving in a host country.