Hi Triton,
There was a bit of a discussion about this previously in 2012 - this is my answer (it was on a thread Road to Loutro, so if you looked for a previous thread about Gavdos, I'm not surprised you didn't find it!)
"Sadly no ferry to Gavdos. It ran (weather permitting) in 2011, but weather did not permit, so when we went this year we were all ready to try to get a few days there. However the ferry had closed down again. There are a couple of boats in the small harbour (a new large harbour has been built since you were there 10 years ago) that advertise trips to Gavdos, but when we enquired in Smyrna Music Bar, we were told he needed a minimum of 15 people to go - as there were only 3 of us, we did not think that we could rope 12 strangers into going along - although it might have been fun trying! I don't know if anyone has any news of whether the ferry will run again."
The ferry must still run for the people who live there, but it doesn't stop at Plakias (unless things have changed - we haven't been to Plakias yet this year). You could ask at the one of the travel agencies in Plakias. I think you will have to stay for two or three nights as the Plakias ferry did not run daily, when it did run. If you got some of that September/October weather others have been talking about, you might not get back!
From what I have read about Gavdos, I'd love to go, but as we are confined to summer months and the Meltemi, I don't think we'll make it until daughter has finished school.
Arnaki