Meet the site
The Arch is a compact but photogenic boulder site just offshore of Moon Island at the mouth of Swansea Channel, built around two large granite boulders, one of which is pierced by a genuine swim-through archway roughly 10 m wide and 3-4 m high. The seabed here is sand scattered with smaller rocks, and the arch itself sits with its northern entrance in about 17 m, while the second boulder rises to within 4-5 m of the surface from a base around 20 m. It's a straightforward navigational dive: drop on the eastern side, work along the reef to the arch, swim through, and loop back around the second boulder — a route that can comfortably be repeated slowly for photography.The site's main drawcard for underwater photographers is the light: with the sun in the right position the archway frames a classic sunburst shot, and the fixed life on the boulders — sea squirts, gorgonian fans, sponges, ascidians and a healthy population of crinoids — provides plenty of foreground interest. Fish life includes large schools of yellowtail and seapike that hold in the lee of the boulders, and at least one very large resident cuttlefish is regularly seen inside the arch itself. Because it's a short, sheltered run from the Swansea boat ramp, The Arch works well as a second dive on a day trip alongside the deeper Swansea-area wrecks, or as a relaxed macro and wide-angle dive in its own right. It isn't heavily promoted or frequently dived compared with the Terrigal reefs further north, which keeps it a quieter option for club groups and private boats out of Swansea.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
The Arch, Moon Island is recorded as Reef in Newcastle & Lake Macquarie. The listed access is boat. 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.
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 The Arch, Moon Island suitable for my certification?
The record lists Advanced 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 The Arch, Moon 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
Large yellowtail and seapike schools, large resident cuttlefish, gorgonian fans, sponges, ascidians, crinoids
Location
A boat dive a few minutes out from Swansea Channel around Moon Island, centred on two large boulders, one pierced by an archway about 10 m across and 3-4 m high.
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
michaelmcfadyenscuba.infodivenewcastle.com.augreynurse.com.augreynurse.com.aumichaelmcfadyenscuba.infomichaelmcfadyenscuba.infoRecord updated 27 Sept 2026. Source claims are being reviewed.