We are planning to fly into Athens in mid September and want to visit Mykonos, Crete, and Santorini...where can we find info and rates on high speed boat travel through these islands? Also, would 12 days be enough to spend on these 3 islands? Thanks!

Hello, There is a Greek site called Greek TravelPages that has a page where I think you can find the boat info. You can view all the available ferries, hydrofoils, and catamarans with itineraries within Greece. I didn't check it for your request, but I was on it just before logging in here, because I am booking to Crete from Pireaus myself (and want to do Santorini right after Crete. I didn't think about the high speed boat option. The link to ferry and other boat site is:
http://www.gtp.gr/greekferries.asp
I have travelled to Crete and Santorini from Athens, and, when confined to the traditional ferries, we were able to do several days on three islands, and 3 in Athens, in 15-16 days, very nicely. (We did 1.Crete, Santorini and Athens, on one trip, and 2.Crete, Santorini, Samos and Athens on a second, and finally, 3.Crete, Rhodes, Patmos, and Athens on a third. The Athens piece was brief, but we did an overnight to Delphi, which was lovely if you like a quiet night in your trip. If you do three islands, expect little to no time in Athens. For the island of Santorini you need 3, and as for Crete....oh, you can spend a month there and not run out of outstanding places to explore...don't shortchange Crete even for Santorini, and certainly not for Athens.
Sophia

The info you are looking for can be found at http://www.ferries.gr/hfd/. For highspeed travel from Athens (Piraeus and Rafina) to and from these islands, do some research on http://www.gtp.gr/. Ferries to Crete and Santorini leave from Piraeus, while ferries to Mykonos leave from both Rafina and Piraeus.

By the way, mid September is absolutely the best time to go to all the islands on your list, unless you like throngs and noise.

Thanks for all the help! I think we're going to spend most of our time on the islands