Foreign Courtesy Flag / Visitor Flag - Mexico
Dimensions: 12" x 18"
These small craft courtesy flags are the specified "civil ensign" of Mexico in proper design and proportion. They're made with brass grommets and 100% SolarMax nylon. This material, developed especially for the flag industry, is engineered to resist damage from the sun's UV rays. Note that the civil ensign or Merchant Flag of any country is not necessarily the national flag of that country.
As a gesture of courtesy, visiting cruisers should fly the specified courtesy flag of their host country when they enter and operate in its waters. Generally, cruising yachts under 60 feet select 12" x 18" or 12" x 24" flags. Larger yachts may select 16" x 24" or larger flags. There is no size requirement, so if you prefer the look of a larger flag, then fly it. However, make sure that it clears a 360-degree fly from your spreader halyards (sailboat/powerboat) or bow (powerboat), or that flag will soon be in tatters.
As noted in Chapman's Piloting & Seamanship, a visitor flag is normally NOT hoisted until the vessel is properly cleared by customs and immigration. Until clearance is complete, fly the yellow Q (quarantine) flag.