The rank structure of the Explorers is entirely voluntary. The purpose is to record progress in skills, knowledge and a ready reference of abilities. A Gray knows more and can do more than a Recruit. This in no way should infer that a Gray outranks a Blue or a Galaxy Level outranks all other levels. The subordinate, superior relationships are all determined by election to leadership positions with the rank structure only as a guide to the abilities of the candidates.
The Explorers are divided into two Grades: Blue and Gray. The Grades are determined by age and years in the program. Boys and girls may join the Explorers at age 12. While they are twelve, thirteen and fourteen they will be Blues. A 15 year old with one or more years in the program will be advanced to the Grade of Gray. No one may be in the Gray Grade with less than one year in the program. When a young person reaches the age of 18 they may no longer participate in the program as a youth member.
The progress awards are usually thought to be divided into three for each Grade, but that is only convention and not any sort of rule. Explorers who are active and are constant members of the program will advance regularly. The progress awards are Recruit, Second Class, First Class (these are traditionally Blue Awards), World, Star and Galaxy.- Excerpted from The Explorer Troopmasters’ Handbook twelfth edition