If you land on Santorini airport you can get to Ios by boat in just 2 hours (Flying Dohlpin 45min). From Santorini airport to the port you can travel by taxi or bus. If you take a taxi the price is max 15 euro - 4 persons (15 min trip).

You will find 6-8 cafe´s/bars at the port where you can relax while you are waiting for the boat.

Blue Star Ferries offers a comprehensive website with information for prices, departing hours to and from Ios and sales agents contact information.
Click to Domestic Lines/Cyclades and there you go!

Hellas Flying Dolphins is another company taking you to Ios. Search for available routes and book online or play with their Interactive route map.

Greek Ferries
Boat or Ferry to and from Greece, including the Greek islands.

GTP, Greek Travel Pages
More than 30,000 sea schedules

Another option called Jet One is available for 37 euro a person. It´s a very fast Ferry with plane-like seats and a mini bar. Jet One is the fastest way to get to Ios but the most expensive.

The ferry schedules available on the Net (and from MOST sources) should be uses as guides and should not be considered concrete in any case. The summer schedules for the most part are not published unlit mid-May and then some of the routes published are still awaiting government approval when they begin operations.

During the summer months ferry companies change their routes adding island to some routes and deleting islands from others. The only schedules that come close to being accurate are the ones you find posted at the port by the port police and then they will only have the next two or three days posted.

Arriving Once you get off the boat, a whole heard of people try to get you to stay at their place, you could talk to them, instead of going in search by your self for accommodations. They'll show you pictures and you can negotiate with the price.