Meet the site
Mariposa Reef is a shallow reef north of Four Mile Creek that the Marine Life Network guide rates 5 out of 10 as a fairly easy shore dive for people holidaying on the coast. It involves a 100 m beach walk and a snorkel out to a small island, with depths of 3-9 m.
The guide lists crayfish, abalone, Australian salmon, reef fish and kelp beds. It is popular with fishermen, and poor visibility is common, so it is best on calm days and on the northern side of the island.
It suits holidaying divers and snorkellers staying at Scamander or Four Mile Creek.
The north-east coast from St Helens to the Bay of Fires is built of the same orange-lichen granite as Freycinet, and under water it forms rounded boulders, cracks and swim-throughs. The regional guide notes damage from the long-spined black sea urchin (Centrostephanus rodgersii) on several sites; this urchin has spread south with the warming East Australian Current and grazes kelp and weed down to bare 'barrens', so expect patches of bare rock among the weed.
The north-east sees far fewer divers than Bicheno or the Tasman Peninsula. There is no regular charter boat, so most diving is done by Launceston club members and visitors towing their own boats, and conditions are checked on the morning rather than booked in advance. The nearest hyperbaric chamber is the Royal Hobart Hospital, more than three hours' drive away; Launceston General Hospital has no chamber, so evacuation planning and oxygen on board matter here.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Mariposa Reef (Four Mile Creek) is recorded as Shore/Rock Platform in Tasmania North-East. The listed access is shore. 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.
- 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 Mariposa Reef (Four Mile Creek) 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 Mariposa Reef (Four Mile Creek) 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
Crayfish, abalone, Australian salmon, wrasse, leatherjackets, kelp beds
Location
A shallow reef and small island north of Four Mile Creek, south of St Helens, reached by a 100 m beach walk and a snorkel out.
Facilities nearby
Roadside beach access; shops at Scamander. St Helens: boat ramps, toilets, supermarket, cafes, fuel and accommodation. Binalong Bay: ramp, toilets, cafe. Air fills unconfirmed locally - nearest reliable fills in Launceston.
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.