North Harbour Aquatic Reserve

This spectacular dive site is well protected and only allows line fishing ( no spearing, traps or collecting) which makes for a great diversity of Sydney marine life.

Quick Facts on Diving North Harbour Aquatic Reserve

  • Location: This reef is located from the inner point of North Head west into the north of Sydney Harbour.
  • Diver Qualifications: Open Water and above
  • Depth: 10m to 36m
  • Recommended Gas: 21% or Nitrox
  • Dive time: Generally, 35-70 mins
  • Visibility: Over 10m to 30m
  • What you’ll see: Soft corals and sponges, weedy seadragons, yellowtail, frogfish, anglerfish, Port Jackson sharks, crested horn sharks, wobbegong, bronze whaler sharks, nudibranch, crimson-banded wrasse, bull rays, whiting, starfish, moray eel, large crayfish.
  • Best season to dive: Great in all seasons

Many scuba dive sites

We offer many dive sites in this area of North Head.

  • Old Mans Hat
  • Adamson Sponge Gardens
  • Red Indian Reef
  • Waterfall, and
  • Fairfax Lookout

We dive several spots along this area and mix up the anchoring depths depending on several factors such as diver certifications, tide height or the incoming or outgoing tide.

The sand line is the best as it gets us under the surface water which is generally dirtier. For coral density, Adamson Sponge Gardens is the best. This dive site is located 15m at the southern end of Old Mans Hat.

Old Mans Hat gets its name from a flat rock that balances atop of the sheer cliff. To old timers the rock looked like a top hat. It’s a spectacular Sydney dive site. It features over 60 species of colourful soft corals and sponges and a large (45-degree angle) boulder field dropping down to a sand line at 18m to 23m.

Frogfish or anglerfish can be seen hiding in wait for their next meal among the coral that are shaped like bowls or vases. The striped anglerfish is the most common, but white-fingered anglerfish and (the black one) the white-spotted anglerfish are also seen on this dive. Anglerfish are very common around the harbour wharves, particularly at night.

There are sharks too on this Sydney dive

Our North Head Marine Sanctuary dive features several species of shark; most notably Port Jackson sharks, crested horn sharks and of course, wobbegong (commonly referred to as carpet sharks.) Very occasionally, we’ll even see bull sharks and bronze whaler sharks cruising at the surface.

Colourful residents and stunning undersea decors

On this spectacular Sydney dive, you’ll find loads of nudibranch, extraordinarily colourful soft-bodied molluscs. In our experience, they typically come in white and black hues. Nudibranch are highly toxic. The bright colours serve as warning for Sydney marine life.

Amazing soft corals

Old Mans Hat includes good-sized caves and swim throughs filled with stunning Alcyonacea or soft corals (formerly known as gorgonian sea fan corals.) These amazing living creatures can grow up to 1.5m in size and come in orange or yellow. They’re much less common nowadays as divers used to collect them for the aquarium trade. The largest one we’ll encounter is 1m in size – and it’s stunning!

Old Mans Hat – a great second dive

We usually explore Old Mans Hat as a second dive, not only due to its beautiful marine life and vivid colours, but due to its location, which is usually calmer and more relaxing.

Kelp gardens start at around 16m in depth and extend up to the 10m deep area where huge boulders are found.

Navigating though this area is like driving around small houses and can be great fun when the visibility is good, generally on the high tide.

An octopus’ garden with sponges!

Octopi can be found in the many ledges of the giant boulders. The sponge gardens are exceptional here due to the nutrients which flow out of Sydney Harbour on the outgoing tide. The water visibility is generally a bit lower in these conditions, but you’ll find a definite change in visibility at about the 15m mark, where the salinity changes from the fresh water near the surface to the saltwater lower down. There is also a thermocline at this depth with a noticeable difference of a degree or two.

With the thermocline comes the visibility changes as the dirtier surface water makes way for the clearer, saltier water below. Visibility varies greatly depending on tides and depths, but expect 10m to 15m most days, and if you’re very lucky, you could even hope for 25m or more once a month.

Red Indian Fish can be found in this area. They’re rare in Sydney due to the aquarium trade and are easily recognisable by their colourful main which looks a lot like an American Indian ceremonial feather head dress.
Dwarf Lionfish also abound. You’ll mainly see them at night in vase or bowl-shaped coral.

Spiny or red gurnards can also be seen in numbers around February. These fish have Freddy Kruger-type “flingers” on the mid-sections of their brightly coloured pectoral fins. The gurnards will walk around the sand lines of Old Mans Hat or off a number of wrecks located in and around the harbour entrance such as the Paddle Steamer PS Herald.

The Catherine Adamson Wreck

The Catherine Adamson (source: Shipwreck Atlas of New South Wales)
Near Old Mans Hat is where the Catherine Adamson sank on the 24 October 1857. It remains one of Sydney’s worst naval tragedies. Built in 1855 in Great Britain, the Adamson was 768 ton and 52m in length. Rumour has it that the ship was carrying the year’s supply of gold sovereigns. The Captain was said to have been drunk on rum. A tug was sent out to try and keep the ship of the rocks, but lost the fight and passengers dies. Shipwreck material is strewn throughout the area, including a large admiralty pattern anchor. This anchor had a wooden stock at its head and can be found among Old Mans Hat boulders.

A protected wreck

A tall ship with North Head in the background

Classified as a ship, the largest of the old wood-hulled types, the Adamson had a complement of 3 masts (foremast, mainmast, mizzen mast), each fitted with a topmast, top-gallant mast and royal mast (each square-rigged.) This wreck site is protected under the Shipwrecks Act. Taking any artefacts is strictly forbidden.

Off the sand line extending out are flat rock plateaus with soft corals and hard corals which support marine life like the weedy seadragons. On this part of the dive, you’ll also find the spiral eggs of the crested horn shark. The shark’s egg has a twisted tendril at its end which the shark attaches to the base of corals or kelp. (Port Jackson shark eggs are very similar. They are fist-sized without tendrils. The sharks will jam the eggs into rocks cracks to let them gestate to term.)

Fairfax Lookout Dive

The Fairfax Lookout dive is located at the inner point of the North Harbour Aquatic Reserve at the entrance to Sydney Harbour. It’s a short 10-minute boat ride from our other dive locations and a great location for a dive as the high headland provides protection from the wind.

At Fairfax Lookout, you’ll find a boulder field on a 45-degree angle which drops down to 18m. At this depth you’ll see gorgeous colourful sea sponges and soft coral gardens. Divers will then make their way towards the reef, edge down a small boulder field to between 23m to 28m where they’ll encounter big black bull rays with up to 3m wing spans, huge schools of whiting and many small caves and swim throughs to explore.

Shipwreck debris

An Admiralty Anchor located seen on our dive to Fairfax Lookout

On this Sydney dive, you’ll discover shipwreck material from several old ships lost in the late 1800s.

A commonly encountered fish on this dive is the crimson-banded wrasse. The female is plain in colour and you’ll find these fish quite inquisitive as they are very much attracted to bright lights.

As this area is a marine sanctuary where commercial or recreational traps are forbidden, you’ll be able to see large crayfish (some over 4kg) during the dive. They will often be seen out walking around divers with little fear. Also on display: moray eels, colourful sea stars (starfish) and nudibranch.

Come dive with us!

Discover the North Harbour Aquatic Reserve with Sydney’s with Sydney’s best dive crew.

Amanda Carroll
Amanda Carroll
20:57 02 Feb 20
We had such an amazing dive with Sydney Dive Charters this weekend - loads of sharks and a Weedy Sea Dragon! So professional, impeccable service, they clearly know the dive sites so well which comes with years of experience and local knowledge, makes such a difference to making a dive good to great, relaxed, efficient easy going. Boat was spotless and well maintained, rental equipment good quality. I look forward to diving with Jason and his team again soon. Thank you guys!
Libby T
Libby T
21:44 27 Jan 20
Great experience with a professional, friendly, and helpful dive team. Jason gave clear briefings, had a great boat set up that is perfect for diving, and provided top of the line hire gear. Jason has great local knowledge, and makes safety a priority. Looking forward to diving with them again.
Chloe et Benjamin .
Chloe et Benjamin .
07:46 26 Jan 20
Amazing diving trip with Jason and his crew! Great gear and logistic. Discovered some of the most beautiful underwater creatures. Jason knows where to find the best spots in Sydney bay and how to improvise when schedule doesn’t go as planned.
Jacintha Symes
Jacintha Symes
04:27 17 Dec 19
Thanks Jason and Kate. We had a great day diving out to the apartments and Coral gardens. On time, will organised, friendly and warm people. Great value ! See you next time Jason !
Andrew Cronan
Andrew Cronan
23:28 16 Dec 19
Great double dive. Quality rental gear and a capable crew. Highly recommended. Andrew
Mick G B
Mick G B
02:33 10 Dec 19
Had a great day diving with Kate. Jason runs a solid operation. Awesome hire gear and boat. Highly recommend
sidney Mendonca
sidney Mendonca
02:20 09 Dec 19
Excellent dive, Jason and kate are very professional and friendly. The boat was comfortable and the dive sites were amazing. I would like give my special thank Jason as I left my wallet on the boat (luckily, it didn't fall to the water) , Jason Found it and called straightway. Thanks mate .
Kasia Brulinski
Kasia Brulinski
15:43 04 Dec 19
Thank you Jason and Kate for an amazing diving experience. As a relative beginner, I was a little nervous about my double-dive, but the team were so friendly and warm that I immediately felt comforable. The diving equipment was all new and state of the art, which made a world of difference, and the dives and visibility were spectacular. I look forward to coming back for more dives with this professional, passionate and kind team. Thanks again!
21:29 02 Dec 19
Well organized, we hired equipment, was good and thrustworty. Enthousiast crew and good dive sites and diving. Mark and Sandra
Rajdeep Roy
Rajdeep Roy
07:55 02 Dec 19
Great day out & a diving experience with Jason. His boat dive instructions are very clear and precise and helps every diver before entry and exit. The best part is when the divers are below, Jason makes sure that there's no other non-diving boat in the vicinity & keeps all the divers feel safe to surface. Gr8 job mate!
Yaofeng KONG
Yaofeng KONG
02:10 24 Sep 19
Amazing experience! Excellent boat crew, caring about the customers. Recommended to everyone!
Claudia Gilbert
Claudia Gilbert
12:01 21 Aug 19
Jason is so knowledgeable and despite being on a course... I learnt a heap from his advice and experience as well... he was also very caring and considerate... which I really appreciated 😉
D Abela
D Abela
11:55 19 Aug 19
This was our third time diving with Jason & Sydney Dive charters and we're looking forward to many more. Jason, a true dive professional, has an enormous wealth of diving knowledge and runs the dives smoothly and safely. We have done a few courses on his dive charters and have the utmost respect for him and the charters he runs. We thoroughly enjoy the diving and information and knowledge we gain every time we dive with Sydney Dive charters.
Paul Kirk
Paul Kirk
11:20 18 Aug 19
I’ve never seen such a well organised, clean and tidy boat which to me, means someone really knows what they’re doing, I’m in good knowledgeable, safe hands and they take pride in their work and I respect that. Jason and his dive boat are a 5-star AAA operation that won’t disappoint.
Javier López
Javier López
22:56 29 Jul 19
Great diving experience. Jason is very knowleadgeable and he made sure our dives were enjoyable and fun. We managed to see Sharks, Weedy sea dragons and many other interesting sea life!. The service is excellent and booking through the web is so easy that it makes the experience even better. I will definitely go with them in my next dives in Sydney!
Meg King
Meg King
09:41 23 Jun 19
Great dive experience with Jason and Xavier. I would highly recommend his service. They took great care of me and all my gear was all top notch. I will definitely be going out with him again.
Arie B
Arie B
05:13 29 May 19
Excellent communication and easy to organise our dives. Professional service with attention to detail. At no stage was anyone rushed to get into the water. Catered for all abilities. Very impressed. Will definitely book again
Roger O'Connor
Roger O'Connor
08:57 13 May 19
Great boat with a amazing crew best dive experience so far with Sydney dive charters i have being out with other dive centers boats and if conditions are not right they will all ways look for the easiest dive site . Even with big swell Jason was happy to go to the dive site we wanted..... Matt was a great guide...... I highly recommend these guys for a great dive experience in Sydney
Ilaria Caccamo
Ilaria Caccamo
09:53 12 May 19
Great diving. Jason is very professional and has great experience that allowed us to dive in safety without giving up a more challenging dive site despite tough weather conditions. He is always dedicated to the customers happiness and safety and always goes an extra mile to help out. Great addition to the team with the Dive Master Matt that perfectly guided our dives today. We saw heaps of sharks and a really giant cuttlefish. The boat is very comfortable and well equipped also with a toilet available. In addition the rental gear available from Jason is excellent quality.
00:56 23 Apr 19
Excellent day out! Highly recommended! I was considering going with another company, and was very happy I chose Sydney Dive Charters instead! New high quality gear, no ripped wetsuits and a good briefing on how to use it all! Jason was very knowledgeable and set us up in the best conditions as he knows the Sydney coast like no one else. Our dive guide was great, he also made the trip very memorable. I will be back again 100%
Raychel Follis
Raychel Follis
18:47 04 Apr 19
Such a good time diving with Sydney Dive Charters. Knowledgeable, professional and fun. They delivered on everything they said. The boat was comfortable and the tanks were full. Thanks again Jason! It was a perfect first dive in Australia, you set a very high standard for us!
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