During a long weekend to Tarragona, in Spain, I decided I should try to get a dive in so I contacted Ody Sea in Torredembarra. It's only 10 minutes on the train from Tarragona and then a walk to the marina. They've got their own cafe if you want breakfast before the dive or lunch after. I hired all the equipment and then I went out on one of their two RIBs to a site called Chaparo.
Chaparo is where several wooden fishing boats have been sunk. There isn't that much in the way of wreckage, but it's a sandy bottom, so it attracts a good amount of life. I saw some grouper, an octopus and even a couple of sea horses as well as the more usual Med fish like bream. Depth was a shade over 18m and they took two RIBs out, I was on the advanced boat, so my dive time wasn't restricted by the less experienced. The dive was over 50 minutes. Temperature at depth was a warm 24C, as you'd expect in August. It was even warmer on the safety stop.
The dive and full equipment cost €49 and it was a good half day out.