All,
Since the forum is always helpful to us with recommendations and advice - time to put some back in!
We found a centre, AquaDivers Club in Anavyssos, around 40min from Athens near the bay of Sunio. We are very happy to recommend it! it's managed by David White from the UK, but they also have Italian, French, Spanish and Dutch speaking DMs. So why the recommendation - and I've dived with various centers in the Americas, Africa, Europe and Asia:
1. safety: excellently maintained equipment and center, and exactly what I'd call "the right attitude". Always considerate to ensure that new divers and experienced divers get full attention. I've in fact done my rescue here now, and the best news was that Mr. White didn't let anyone pass unless done to more or less perfection! If you pay the money to have these skills... you want to make sure you get them!
2. comraderie: both the regular team of divers, and the tourist visitors will enjoy a great team who both have fun - and still do it right. Meaning that the in between dives is almost as nice as the actual dives.
3. flexibility: any problem or issue, the team will fix it! Be it a late schedule adjustment, or getting the engineers to sort out ventilation for the hoodie...I guess its just a case of really good customer service.
So, in conclusion: I cannot comment on whether it's better or worse than the other centers around athens - but I can comfortably say that if you want to spend a weekend diving, or do some course work, I'm confident that these guys won't let you down on any level.
Best to all,
Rikard