Meet the site
The Iron Pot is a small rocky island at the mouth of the Derwent, crowned by the Iron Pot lighthouse, erected in 1832 and regarded as the oldest operating lighthouse in Australia. The Marine Life Network guide describes it as easily reached from South Arm, in 2-15 m, with a sheltered western side and a more dramatic eastern side. At the southern end near the lighthouse the sea has split away part of the rock to create a small 'island' with a swim-through, while the eroded eastern face has many small caves and crevices in about 12 m, with sponge gardens at the base of the wall. Leatherjackets, wrasse, school fish and invertebrates are found around the island, and crayfish, although the guide notes numbers are affected by boat traffic and nets. History is visible too: remains of an old winch used to haul supplies to the lighthouse, and the site where the ketch Caledonia was wrecked. The wreck of the river steamer Lintrose lies nearby in very shallow water. The Iron Pot is one of the best reef dives close to Hobart and a good alternative to the Betsey Island graveyard when conditions there are poor. The swim-through and eastern caves need calm conditions, while the western side is diveable in moderate southerly weather. Visibility varies with the Derwent: clear marine water after a dry spell and a flood tide, dark and murky after floods. It suits Open Water divers on the sheltered side and more experienced divers on the exposed face.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Iron Pot Reef is recorded as Island in Hobart & Derwent. The listed access is boat (day trip). Confirm the actual meeting point, route and permission to visit; a map pin does not establish any of these.
Topics flagged by the stored research
These are questions prompted by the existing notes, not a verified or complete hazard assessment.
- Other water users
- Ask about vessel activity, exclusion areas and the agreed surface arrangements.
- Lines and obstructions
- Discuss any known entanglement concerns and the suitability of the planned area.
- Water movement
- Ask how swell and local exposure affect the proposed entry, exit and route.
Historical access notes exist for this record, but have not been independently verified for current use. Request current directions from the operator or site manager rather than following an old entry description.
Questions, answered
Is Iron Pot Reef suitable for my certification?
The record lists Open Water. That does not establish suitability for every route or day. Share your training, recent experience and equipment needs with the operator and ask about the specific proposed dive.
Can I book Iron Pot Reef through YouDive?
YouDive is an independent research directory. Contact an operator directly to confirm whether it currently runs the trip, the inclusions and the booking terms.
What you might see
Sponges, ascidians, leatherjackets, blue-throated wrasse, schooling fish, southern rock lobster, octopus, sea stars, kelp and brown algae
Location
Small rocky island with Australia's oldest operating lighthouse (1832) at the mouth of the Derwent, off South Arm, with reef, a swim-through and eroded caves.
Facilities nearby
South Arm boat ramp; store at South Arm; fills in Hobart.
Before you make plans
Conditions, access and operator schedules can change. This is a location guide, not a dive plan. Ask a local operator about current conditions and suitability for your training and experience.
Sources & further reading
marinelife.org.auRecord updated 26 Sept 2026. Source claims are being reviewed.