Quarantine Edinburgh and Leith, grain was from that date declared to be a non-susceptible article. About 1788 an order of the council required every ship liable to quarantine, in case of meeting any vessel at sea, or within four leagues of the coast of Great Britain or Ireland, to hoist a yellow flag in the daytime and show a light at the main topmast head at night, under a penalty of After 1800, ships from plague-countries (or with foul bills) were enabled to perform their quarantine on arrival in the Medway instead of taking a Mediterranean port on the way for
Maritime flag which a burgee (tapering flag with swallow-tail fly) is flown when in port. There is a system of International maritime signal flags for each letter of the alphabet, and pennants for the numerals. Each flag (except the R flag) has an additional meaning when flown individually, and they take other meanings in certain combinations. A courtesy flag (or courtesy ensign) is flown by a visiting ship in foreign waters as a token of respect. It is often a small (that is, smaller than the ship's own national ensign) national maritime flag of the host country, although there are countries (such