Santorini

Use local guides for caldera sites, wrecks, caves, night dives, and any new shore entry. Carry an SMB, dive computer, and audible surface signal. Do not surface near boat lanes without a marker. Avoid aggressive depth profiles on arrival day or before flying. Volcanic sand can reduce visibility when kicked, so maintain horizontal trim. Freedivers should never train alone, never mix breath-hold work after scuba without conservative guidance, and always use a buoy, line, and trained buddy for depth sessions.

Santorini General Hospital in Karterados has a 24-hour emergency department. No authoritative source confirmed an on-island recompression chamber for dive accidents, so suspected decompression illness should be treated as an evacuation-class emergency. Get the diver on oxygen if trained personnel and equipment are available, call 112 or EKAB, contact DAN Europe, and coordinate through the operator and hospital. Do not wait for symptoms to worsen after a suspicious ascent, missed decompression, neurological sign, chest symptom, or severe joint pain.

Santorini's water is not managed like a single named marine park for visitors, but conservation still matters. Do not touch octopus, morays, nudibranchs, sponges, monk seals, turtles, or dolphins. Do not enter monk seal caves or chase wildlife. Avoid anchoring damage if renting boats, keep sunscreen and trash out of the water, and use good buoyancy over fragile sponges and algae-covered rock. Greek authorities regulate underwater antiquities, historic wrecks, and activities that could damage cultural heritage. Look, photograph respectfully, and leave everything in place.