El Nino Watch
For each of the next 7 local days: are crossing conditions normal enough to leave by ferry?
Koh Samui watch
Each day combines that day's forecast waves and gusts, TMD Gulf wave bulletins until their end date and, for the first 3 days, a nearby cyclone.
Limits. Wave forecasts beyond 3-4 days are less reliable. The operator's decision on the day is what counts.
ok = conditions look normal. caution = possible, expect delays or cancellations. blocked = ferries likely suspended. unknown = no forecast for that day. Pick the earliest ok day if you plan to leave.
Leaving on a calm day before a rough spell avoids being stuck when ferries stop.