On some occasions, when changing tides or weather forecasts affect her sailings so that she has to leave Penzance at about 10:30, she will leave Hugh Town again around 15:00, and on the few days when she needs to sail from Penzance at about 08:30, she will depart Hugh Town at about 11:15. Times and dates may also change due to school holidays, special occasions and unexpected events. Two sailings a day, Sunday or night sailings are rare and usually only arranged by the Steamship Company when an exceptionally high number of passengers depend on the ferry service. This may be the case on busy weekends at the start of the summer season, around the World Pilot Gig Championships, and more regularly during the year when the air services between the Isles of Scilly and the mainland are grounded due to poor visibility (see "Notable events" below).