Meet the site
The Fossil Cliffs are tall limestone cliffs on the northern tip of Maria Island, famous on land for the dense beds of Permian fossils - mostly shells and bryozoans - that make up the rock. Under water, the Marine Life Network guide describes a sunken sea terrace near Cape Boullanger with a large swim-through, about 4 m wide, 5 m high and 20 m long, at around 17 m, with the sandy fringe as the landmark for finding it. It rates the site 6.5 out of 10.
Bullseyes gather in the swim-through and banded morwong patrol the terrace. Above it, at about 10 m, is a weed garden with typical east coast reef fish - wrasse, leatherjackets, sea sweep and trumpeter. The same fossil-bearing limestone forms the terrace, and fossil shells can be seen in the rock, although collecting is prohibited in both the national park and the marine reserve.
The neighbouring Fossil Bay, to the west, is a shallower site of 5-12 m, and the two can be combined. The swim-through is spacious and not a true cave, but divers should still avoid it in surge.
Fossil Cliffs suits Open Water divers comfortable with boat diving and a short overhead section. There is no dive operator on the island, so visitors need their own boat or a club trip from Triabunna.
Maria Island is a national park with no permanent residents apart from rangers, and the Darlington settlement preserves convict-era buildings from 1825 onwards. The marine reserve along the island's northern and western shores has been no-take since 1991 and has been used for long-term studies of how protection affects rock lobster and fish numbers, so reef life inside it is noticeably richer than outside.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Fossil Cliffs (Maria Island) is recorded as Wall in Tasmania East Coast. 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.
- Water movement
- Ask how swell and local exposure affect the proposed entry, exit and route.
- Overhead environments
- Ask whether the plan stays entirely in open water. A wreck or cave listing is not permission or training to enter.
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 Fossil Cliffs (Maria Island) 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 Fossil Cliffs (Maria Island) 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
Bullseyes, banded morwong, wrasse, leatherjackets, sea sweep, trumpeter, butterfly perch, weed garden, fossil shells in the limestone
Location
Sunken sea terrace and a large swim-through below the limestone Fossil Cliffs near Cape Boullanger, northern Maria Island, inside the marine reserve.
Facilities nearby
Darlington: toilets, showers at the Penitentiary accommodation, campground, ranger station, no shop or air fills. Triabunna: ramp, fuel, supermarket, cafes. Nearest air 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.auen.wikipedia.orgtsdc.org.auRecord updated 26 Sept 2026. Source claims are being reviewed.