Safety · Destination Guide
Cold-water kelp forests, a no-take marine reserve, and Great Walk wilderness in New Zealand's Deep South
Updated Feb 13, 2026 • 21 sources
Stewart Island diving and adventuring is remote, cold-water, and weather-led. The safest trips assume delays, carry redundant safety gear, and follow conservation rules to the letter, especially in the Ulva Island / Te Wharawhara Marine Reserve.
Stewart Island has a small local medical service in Oban for primary and urgent care, with limited resources compared with the mainland. For serious injuries and dive emergencies, evacuation to the South Island may be required.
Because help is remote, bring a well-stocked first-aid kit for boating and tramping, and do not dive or hike beyond your ability to self-manage for a longer period than usual.
Foveaux Strait sea state and cancellations
The ferry crossing is short but can be rough, and both ferries and small-plane flights can be delayed or canceled by wind, low cloud, and sea state. Windy fronts (30 km/h+ on exposed days) are common in winter. Build buffer time and carry seasickness medication if needed.
Cold water and rapid chilling
Most in-water sessions are limited by temperature, not air. Use thick neoprene or a drysuit, shorten sessions, and warm up early. Cold can also reduce breath-hold performance and increase risk.
Limited scuba support on-island
Do not assume you can rent a full scuba kit, get specialty parts, or find last-minute fills. Bring spares and confirm logistics before you leave the mainland.
Sandflies in calm, damp conditions
Biting sandflies can be intense around sheltered bays, especially when there is little wind. Pack repellent and cover up at dusk.
Stewart Island's underwater highlights exist because the ecosystem is still functioning. Protect it.
Do Not Do This
Avoid entering when foveaux strait sea state and cancellations. Confirm local briefings before committing.
| Contact | Role | Phone | Availability |
|---|---|---|---|
| Emergency Services | Police, Fire, Ambulance | 111 | 24/7 |
| Diver Emergency Service (DES) | Dive medicine hotline | 0800 4 337 111 | 24/7 |
| Stewart Island Medical Service | Local clinic | +64 3 219 1098 | Clinic daily (limited hours); on-call support available |
| Coastguard New Zealand | Marine rescue | 111 (urgent) or VHF Channel 16; *500 for non-urgent from a mobile | 24/7 via emergency channels |
| Rescue Coordination Centre New Zealand (RCCNZ) | Search and rescue coordination | 0508 472 269 | 24/7 |