Unless you have a car, the best way to get to Ærø is the ferry from Svendborg to Ærøskøbing. Through June 2008, ferries will depart Svendborg Monday-Friday every 3 hours from 07:30 until 22:30. On most weekends, the 07:30 ferry doesn't run. Travel time is approximately 1 hour. The return trip from Ærøskøbing departs Monday-Friday every 3 hours from 05:55 until 20:55; no 5:55 departure on weekends. Service is further limited around Christmas and New Year's Day.
Updated Fares September 2008: Through June 2009, passenger fares are DKK 114 per adult 1-way, DKK 175 round trip Children cost DKK 72/DKK 102, while Seniors are charged DKK 86 / DKK 127. If you're taking a car, passage is an additional DKK 247 one-way, DKK 386 round trip, reservations are highly recommended but at no charge. walk-on passengers need not make reservations. Group and multi-ride deals are available; check the website for details.
There are 6 daily ferries going from Svendborg to Ærøskøbing (4-5 in the weekends).
The current prices (december 2006) are:
Adult DKR 92/149 (single/roundtrip).
Other combinations can be see on the shipping companys homepage.
The ferry departs from a dock near the railwaystation in Svendborg, and you can follow the signs from the station to the ferry.