Hi If you shore dive say from Cirkewwa you pay a flat rate and most dive company's seem willing to pick you up within a reasonable distance ( lets say the next town or two from the one you are staying in ). So if staying in Mellieha the Cirkewwa dive is lets say 40 euros for one dive including equipment ( this would include diving the P29 or Rozi as these can be dived from shore) if you dive say the MV Pippo or the MV Imperial Eagle you would pay an extra 10 euros for each dive ( some may cover two dives for this price but you need to ask each dive centre ). If you dive the HMS Hellespont near Valletta then this boat dive would be 15 Euros more per dive. If you decide to do a Gozo dive and they drive over via the ferry then that is 20 Euros extra some charge extra for boat dives from Gozo it just comes down to costs of travel ie using the ferry and distance traveling in a boat. If you are renting a car it may be better if diving both the North and south of the island to book the Northern dives with a dive centre in the North and a dive centre based in the South for the Southern boat dives etc. Not heard of one bad dive centre in Malta so far ( spoke to quite a few from Qarwa northwards ) but I can add to those recommended above as I used Aquaventure based at the Mellieha Bay hotel. Sorry can not add much more I would recommend looking on the websites for all the dive centres mentioned or ask about dive centres in the area you plan to stay and dive and then drop them an email re your requirements, almost every one I emailed replied within 36 hours.