They are close to the equator, another reason is because of the tropical maritime location, temperature changes throughout the region are generally small.
Looking at a globe or an adjusted flat map
Lingua Franca is a language that people of different languages use to communicate. The answer is English.
It shows what certain symbols or pictures could mean on a map, and in addition, could show a scale that converts inches or centimeters that you can measure with a ruler to miles.