Hi,
I have just come back from diving in Malta last month, mid June. I did my dives with a company called Delfini Dives in St julians bay which is about 15mins from Valleta. Most of the dives in Malta are from the shore. I did 2 dives on the Maori which is a good dive to get back in the water if you havent been for a while, but there wasnt too much to see. I did my wreck specialty so it was great for skills practice.
My next two dives were on the Um El Fraud which is off the south coast of malta, you get to it by the Blue Grotto, the bottom sits at about 30m, it was my first big wreck and I was in awe. it has great swim throughs and is good to explore. You definatly need more than one dive on it though, its so big. 2 other dives from Malta that I was really keen to do but ran out of time for was the P29 (shore dive) and the bristol bomber (boat dive).
My other dives took place from Gozo, once again all shore dives, or rock climbing dives which was a bit warm in the sun at times but always worth it when I got in the water. There are so many really good diving places in Malta, and I am dying to get back, It has been one of my best diving holidays so far, up there with Egypt and New Zealand. There isnt a huge amount of sea life, not what I am used to anyway but seeing big schools of large fish definately made up for it.
I really hope you enjoy your holiday as much as I did. I checked out about 5 different dive companies while I was there and they all seemed about the same price, around 35-40 euros per shore dive with guide and transport.