The island of Pag is very attractive for scuba or apnea diving. Especially interesting is the outer side of islands. From Mandre you can visit several excellent diving locations, if you rent a boat or find someone to take you to location. There is also the possibility of an organized diving with a guide, individually or in a group.
If you want to engage in underwater fishing, beside the equipment license is needed, which is the easiest to get here. Note: Scuba diving and spearfishing is strictly prohibited.
Map of diving locations in Zadar area you can download and view in PDF: