Safety · Destination Guide
Volcanic walls, lava caves, clear Aegean water, and a world-class caldera topside
Updated Apr 26, 2026 • 25 sources
Santorini is generally straightforward to visit, but the island combines sea, cliffs, volcano terrain, summer heat, boat traffic, and protected underwater cultural heritage. The biggest water-planning risks are wind, sun, dehydration, rough entries, and assuming a named dive site will run regardless of conditions. Use licensed operators, follow 112 alerts, and treat any suspected decompression illness as an emergency requiring oxygen, evacuation planning, and DAN or hyperbaric consultation.
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.
Meltemi wind can change the water plan
In peak summer, north winds can create chop, ferry disruption, and dive-site changes. Book with operators who have multiple sheltered options.
Red Beach cliffs and paths need caution
The red volcanic cliffs are beautiful but unstable in places. Prefer boat access when warnings, heat, crowds, or poor footwear make the walk risky.
Heat and sun exposure are serious
Black sand, lava rock, volcano hikes, and caldera trails can be brutally exposed. Carry water, cover skin, and move hikes to early morning.
Underwater antiquities are protected
Do not touch, move, photograph commercially, or collect artifacts from wrecks or archaeological contexts. Use licensed local dive centers for regulated sites.
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.
Do Not Do This
Avoid entering when meltemi wind can change the water plan. Confirm local briefings before committing.
| Contact | Role | Phone | Availability |
|---|---|---|---|
| European Emergency Number | Police, fire, ambulance, coast guard routing | 112 | 24/7 |
| EKAB Ambulance | National emergency medical aid | 166 | 24/7 |
| Hellenic Coast Guard | Marine emergency | 108 | 24/7 |
| Santorini General Hospital | 24-hour emergency department, Karterados | +30 22860 35300 | 24/7 emergency department |
| DAN Europe Emergency Hotline | Diving emergency medical consultation | +39 06 42115 685 | 24/7 |