Meet the site
Old Man's Hat is named for the hat-shaped rock on the skyline of North Head's inner cliff, and beneath it lies what most Sydney divers regard as the best sponge garden in the harbour. The headland runs east–west for about 1.5 km and the reef below it is a broad apron of small boulders on sand cut by low walls, with much bigger boulders off the reef edge forming very spectacular walls, overhangs, small canyons and a couple of very good swim-throughs. The sand edge sits at 22–24 m and deepens toward the ocean; the interesting structure is between 12 and 22 m. Sydney Dive Charters describes it as a boulder field 'with colourful tulip and vase soft corals'. The fixed life is the reason for its reputation. Sponges of every colour, sea squirts and ascidians, gorgonian fans, sea tulips and soft corals cover the shaded faces so densely that the rock disappears; basket stars unfurl on the fans at night. Among the mobile life, bream, sweep, luderick, yellowtail and black-reef and six-spined leatherjackets are constant; weedy sea dragons live on the sandy fringes; red indianfish are found occasionally; wobbegongs and bull rays lie in the gullies; and in late winter Port Jackson sharks pack into the overhangs in large numbers. Moray eels, crayfish and blue groper complete the picture. The Centurion clipper struck the rocks here in 1887 before sliding off into deeper water (her remains lie nearby off Quarantine Point), so the site has history as well as colour. Being on the inner face, Old Man's Hat is diveable in almost any north-easterly weather and is the classic 'plan B' that turns out better than plan A. The tidal current along the wall sets up an easy drift. It suits Open Water divers upward, photographers of all persuasions, and night divers; it is inside the North Harbour Aquatic Reserve, where spearfishing and collecting are banned.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Old Man's Hat (North Head) is recorded as Reef in Sydney Northern Beaches. 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.
- Current and timing
- Ask how the operator assesses the current window for the actual route. Historical tide notes are not a departure instruction.
- Other water users
- Ask about vessel activity, exclusion areas and the agreed surface arrangements.
- Planned depth
- Confirm the intended route and training requirements; the recorded maximum is not a target.
- 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 Old Man's Hat (North Head) 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 Old Man's Hat (North Head) 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, gorgonian sea fans, sea tulips, soft corals, basket stars, weedy sea dragons, red indianfish, Port Jackson sharks (late winter), wobbegongs, bull rays, moray eels, blue groper, crayfish, leatherjackets, bream, sweep, luderick, nudibranchs
Location
Boulder field, walls, swim-throughs and sponge gardens below the hat-shaped rock on the inner (harbour) face of North Head, 12–24 m; the best-known dive in the North Harbour Aquatic Reserve.
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.infodivesydney.com.ausydneydivecharters.com.audiveplanit.comRecord updated 27 Sept 2026. Source claims are being reviewed.