Cave diving in Croatia

• Sea diving: through a registered dive centre or diving club. Independent divers need an 'odobrenje za individualno ronjenje' from a harbour master's office (lučka kapetanija Pula, Rijeka, Senj, Zadar, Šibenik, Split, Ploče or Dubrovnik): per the ministry's page 2,400 kuna (~€320), valid one year — check the current euro fee. Mark your dive with an orange/red buoy (≥30 cm) or a dive flag; separate bans apply at wrecks and archaeological zones. • Inland springs: the deep springs are protected (Izvor Cetine natural monument since 1972, Vrelo Une since 1968, Izvor Kupe in Risnjak NP) and often drinking-water sources. Swimming is banned at the Cetina spring (since 2022, 400 m downstream) and at Vrelo Une (entry €3). Divers were fined for unauthorised diving at the Cetina in 2009. No operator offers recreational spring dives: plan it as an expedition and get permission first (municipality, Hrvatske vode, the county nature-protection body — Natura Jadera for the Una — or the national park). • Vrulje (submarine springs): Modrič (~2.9 km) and Zečica (1.2 km) near Rovanjska were explored by foreign teams with CCR and scooters, under a Croatian diving permit and with local cave divers; halocline, clay and 2–8 m visibility. • Kornati NP: independent diving is banned; only with one of the 7 contracted centres (2026), in 9 zones, max -40 m, no night dives (19–07 h). Just Dive (Biograd) charges a €38 park surcharge. • Water: springs 5–11 °C year-round (Kupa 5–7 °C, Cetina ~8 °C, Una avg 9.5 °C). Sea in the north (Istria) ~9 °C in April to ~20 °C in September; around Brač 17–27 °C. In vrulje cold fresh water (~9.5 °C) meets warm seawater (~21 °C). • Gas and CCR: trimix and O₂ at Kron Diving (Rab; rEvo training centre, full rebreather support), Kornati Diving Center (Sali, Dugi otok; booster), B-24 (Komiža, Vis; up to 300 bar, rental CCR ISC Megalodon/Pathfinder €80) and Just Dive (Biograd; O₂ and helium per 100 l). No fill station was found around Knin/Vrlika — bring your gas from the coast. In Split, LUK Technical Diving (Andrija Lukenda, +385 98 990 3231) teaches JJ-CCR and trimix; ask about fills. • Accident: call 112. HGSS (mountain rescue) has its own cave-diving rescue team. Chambers: KBC Rijeka, Centre for Underwater and Hyperbaric Medicine, Tome Strižića 3, Rijeka (Sušak), +385 51 407 435 — team reachable 24/7 (sessions Mon–Fri 08–16 h, weekends emergencies only). OXY Pula, Santoriova 24a, +385 52 215 663 (office Mon–Fri 07:30–15:30; 24 h numbers +385 98 219 225 / +385 98 381 693 per a 2022 list). Split: chamber of the Navy's Institute of Maritime Medicine (IPM HRM), Šoltanska 1, +385 21 354 511. Dubrovnik: OXY, Dr. Roka Mišetića 2, +385 20 431 687 (24 h: +385 98 381 685, 2022 list). Zagreb: OXY, Makarska ulica 5. OXY is contracted by the Croatian health fund HZZO. DAN Europe +39 06 4211 5685. • Bases: Knin or Vrlika for the inland springs; an island base for the sea caves (Komiža for Biševo, Split for Šolta/Brač, Mali Lošinj or Zadar for Premuda and Dugi otok) — the islands are reached by ferry.