More ships ... and Definitives too

A 'Definitive' stamp is, according to Wikipedia

... a postage stamp, that is part of a regular issue of a country's stamps (often referred to as a 'regular issue') available for sale by the postal service for an extended period of time.

I like definitives. They are a series of stamps, often with the same image in different colors. The Machins, the US Presidential series, and this set from Portugal issued in 1942 depicting a sailing caravel. I found these in a set of Portugal stamps I purchased at a stamp show ... it is not a complete set (although that is on the way).