Meet the site
Six Fathom Reef, also called Simpsons Reef, takes its name from its shallowest point – about six fathoms, or 11 m. It sits right at the mouth of Port Hacking north of Jibbon Point in Royal National Park, and its great strength is shelter: Jibbon Bombora blocks the southerly swell, so it is generally the fall-back dive when rough seas close the open coast, and its shallow depth and proximity to the ramps make it a handy second dive. The reef rises gradually from a sandy bottom at about 24 m to its 11 m top. Small walls of one to two metres ring it, with small overhangs and a couple of little swim-throughs. The western side is the most interesting, with a series of steps: the main wall rising about 5 m, a mid-level wall at 17 m and a deeper wall at 21 m, with sand at almost 27 m below. Fish life is abundant: ladder-finned pomfret, bullseyes, yellowtail, seapike and one-spot pullers in huge numbers, with bream, yellowtail kingfish, trevally, blue gropers, red morwong, eastern blue devils, black reef leatherjackets and wobbegongs, and Port Jackson sharks in spring. Sponge gardens, gorgonians and lace corals are best on the southern and deeper sections, and rarer sightings include pineapplefish and giant boarfish. A circuit of the reef takes about 20 minutes, and crossing the top allows different routes back to the anchor. Tides do not greatly affect the site, but runoff after heavy rain can dirty the water. It suits Open Water divers looking for a sheltered, fishy dive and experienced divers wanting a bad-weather option that is better than its reputation.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Six Fathom Reef (Port Hacking) is recorded as Reef in Sydney South & Botany Bay. 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.
- 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 Six Fathom Reef (Port Hacking) 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 Six Fathom Reef (Port Hacking) 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
Ladder-finned pomfret, bullseyes, yellowtail, seapike, one-spot puller, bream, yellowtail kingfish, trevally, eastern blue groper, red morwong, eastern blue devil, black reef leatherjacket, wobbegong, Port Jackson shark (spring), pineapplefish, giant boarfish, sponges, gorgonians, lace corals
Location
Reef at the mouth of Port Hacking north of Jibbon Point, rising from 24–27 m sand to about 11 m (six fathoms), sheltered from southerly swell by Jibbon Bombora.
Facilities nearby
Departure only: Port Hacking ramps – Tonkin Park/Gunnamatta Bay (Cronulla), Lilli Pilli, Grays Point – with parking and toilets; air/nitrox at Pro Dive Cronulla (Gerrale Street) and Abyss (Ramsgate).
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.infoRecord updated 27 Sept 2026. Source claims are being reviewed.
