I got my PADI open water certification about a year ago and did some dives after certification. Because I feel my skills need quite some improvement, I'm looking to take a trip to get my PADI advanced open water certification and do 4 to 6 additional guided dives. Therefore, I'm looking for a location where diving is good in September or October. The location should be easily reached from Amsterdam; preferably a direct flight of a few hours and not too much post-flight travel. Because I don't drive, remote places are not really an option, and I prefer to stay somewhere where I can walk to the dive shop as well as to restaurants and the supermarket.
So far I've looked into Malta and the Canary Islands and for now Malta has my preference because it's most easy to reach and the flight times are very convenient. For this option, I find it hard to choose between going to Gozo (Marsalforn) or staying in the St Julian / Sliema. For the Canary Islands I spent some time looking into diving from Gran Canaria and there the interesting options are diving from Las Palmas or going to a shop near El Cabron.
I hope to get some suggestions on where to go, also for any places that I didn't mention. Any suggestions for dive shops are also welcome. TLDR; I'm looking for a dive location for 4-5 days of diving in September/October that is easy to reach from Amsterdam.