The thermal spring works even during rainy winter days. The water temperature around the spring stays at about 25°C in winter, while the surrounding sea is around 15°C. In summer, the temperature is approximately 29°C everywhere. Bojan Runtic offers rich Adriatic marine life across different depth zones. In the shallow waters from 0–20 meters, common species include salema, seabreams, wrasses, octopus, cuttlefish, moray eels, scorpionfish, seahorses, starfish, sea urchins, and sea cucumbers. These sheltered shallows are ideal for snorkeling, beginner divers, and underwater photographers. At depths of 15–25 meters, the underwater landscape becomes more dramatic, with rocky reefs and small caves creating beautiful light contrasts across the colourful benthic environment. Typical species found here include yellow and orange sponges, small gorgonians, sea squirts, lobsters and squat lobsters hidden in crevices, as well as schools of damselfish and small anthias around the reef edges. These areas provide excellent conditions for intermediate divers who enjoy exploring natural underwater formations.