Cres and Losinj combine local day-boat diving with sheltered training bays, clear rocky coves, vertical walls, compact caverns, and deep wrecks. Base in Mali Losinj for Cikat Bay, Artatore Reef, Srakane Wall, and Susak Secca Margarina, or on Cres for house-reef routines and the advanced Lina Wreck. The islands are joined by road at Osor, so a rental car can support a two-base trip, but boats and site choices still depend on wind.
May to June and September are the easiest all-round months. July and August bring the warmest swimming conditions and fullest schedules, along with the greatest heat, traffic, and booking pressure. Non-divers get a strong parallel itinerary: Blue World dolphin education, the Museum of Apoxyomenos, Beli's griffon vultures, coastal walking, village exploration, and wellness around Cikat or Veli Losinj. This is a local-operator destination, not a liveaboard-led itinerary.