The term “Junior” in sailing has a very specific meaning as outlined below, but in general for the ECSA it’s defined as the sailor cannot reach 19 years of age in the current calendar year.  Unless the regatta announcements specify otherwise expect that only Junior sailors will be racing at Junior events.

Full time paid sailing instructors may sail in the All Star Regatta and Team Racing provided they are legitimate members of the club or association they represent and cannot reach 19 years of age in the current calendar year.

In the Opti fleet the official IOD (Optimist Dinghy) Class Association age groups are supported by the ECSA and are based on the age of the skipper’s on the first day of the regatta:

White Fleet – 10 and under

Blue Fleet  -11 and 12

Red Fleet – 13, 14 & 15

Green Fleet 15 and under.  Please see this link for more details on Green Fleet Sailing.

Also listed are age restrictions for other ECSA and US Sailing sponsored events:
ECSA Midgets Must be 15 years old or younger on the the days of the final event.

ECSA All Star & Team Racing can not reach 19 in current year

US Sailing Juniors must reach 13, but not 19 in current year

US Sailing Youths cannot reach 20 in current year