Results of my research..
Diving in Ibiza, yes, heard it was okie and I will give it a try in july.
As for Greek islands, a lot of wrecks but marine life aint that great so perhaps I will stay dry and get drunk.
As for Croatia, im looking at some diving at hvar island. not sure yet since I don't have any onformation as yet.
Malta, I don't have budget ah. maybe next time.