October to December in both theatres, which is delivery and refit season rather than racing season. The Mediterranean season from May to September, and a Caribbean season from January to April that is a genuine second peak rather than a fringe.

Sailing is one of the few rows with two full hemispherically-driven seasons of comparable size. Crew berths are filled two to four months ahead through class and club networks, sometimes later.

Charter boats and marina berths are booked a year ahead. Accommodation in small regatta towns is the binding constraint and goes first.

Yacht clubs as the formal institution, class associations which are the real communities, crew-finding networks, and the regatta village bar. Sail together weekly at a club, form crews that persist for years, deliver boats between venues as a shared task, and reconvene at the same regatta week annually.

The June and September Mediterranean regatta weeks, the August British regatta week, the spring Caribbean circuit culminating in the late-April Antigua week, and the June Baltic week.