The Great Barrier Reef

The Great Barrier Reef is one of the world’s most amazing and unique natural spectacles. Visible from outer space, this 348,000 km2 Natural Wonder of the World is a must for everyone to experience. It extends for some 2,300 kms along the north eastern coast of Queensland, Australia, to Bundaberg in the south. To put it in perspective it covers an area about the size of the United Kingdom or the length of the entire Japanese Island chain.

The Agincourt Ribbon Reefs where Poseidon operates are 70km North East of Port Douglas and are long narrow reefs located along the very Outer Edge of the Great Barrier Reef. Being some of the most pristine areas of the entire Great Barrier Reef they are home to thriving coral gardens, a huge variety of marine life and some of the best reef snorkelling and diving opportunities in the world.

To learn more about the reef visit our friends at Reef Biosearch.

Dive & Snorkel Site Map

Poseidon has access to an amazing selection of over 35 ecologically diverse and spectacular Agincourt ribbon reef sites, and Escape Reef, at the very outer edge of the World Heritage Great Barrier Reef.

These special reefs known as 'ribbons' run parallel to Australia's Continental Shelf and are recognised as amongst the most pristine eco-systems in the entire Great Barrier Reef Marine Park.

Clear outer reef water provides the best possible underwater visibility, encourages rich coral growth and supports spectacular marine life and enable us to offer some of the best possible day boat diving. This includes drift and wall dives, isolated pinnacles surrounded by pelagic fish, and coral gardens with their endless variety of colourful wrasses, cods, parrot fish, clown fish, angel fish, clams and anemones, that make a health living reef so beautiful and exciting to dive.
Agincourt Reef 1
Agincourt Reef 2
Agincourt Reef 3
Agincourt Reef 4

Agincourt Reef 1

The Agincourt reefs are a cluster of distinctively separate reefs. Located at the southern end of the Agincourt reefs chain, Agincourt Reef 1 showcases rich coral diversity and marine life.

Rating:

Novice - Intermediate

Visibility:

8 - 35 Metres

Depth:

5 - 24 Metres

Whaler Point
Location: Agincourt Reef 1

Maximum Depth: 20m

Visibility: 8 - 30m | Average: 15m

Site: The southern end of Agincourt reef 1, this beautiful site is rich in coral diversity - boulder, staghorn, plate and abundant soft corals.

Marine Life:
  • Sharks
  • Rays
  • Barracuda
  • Oceanic Sweetlip
  • Parrotfish
  • Drummers
  • Heaps of small shoaling fish
Castle Rock
Location: Agincourt Reef 1

Maximum Depth: 24m

Visibility: 8 - 35m | Average: 15m

Site: An unusual patch reef with a 24 metre exposed wall and spectacular garden reef on the lee side of the reef. Because of its location, a variety of larger marine life tend to congregate here.

Marine Life:
  • Sharks
  • Rays
  • Groper
  • Oceanic Sweetlip
  • Oceanic Trout
  • Moray Eels
  • Anthias

Agincourt Reef 2

From the stunning Nursery Bommie, regarded as one of the best dive sites in the region, to wall diving at Izzy’s Wall, here’s a snapshot of some of the amazing site that Silversonic visits at Agincourt Reef 2.

Rating:

Novice - Intermediate

Visibility:

8 - 30 Metres

Depth:

5 - 30 Metres

The Gardens
Location: Agincourt Reef 2

Maximum Depth: 10m

Visibility: 12 - 30m | Average: 20m

Site: Shallow lagoon site with a mass of boulder corals scattered over the bottom. We often drift this site allowing us to see a large area of the reef. The current also means that the visibility is often exceptional.

Marine Life:
  • Parrotfish
  • Goatfish
  • Milkfish
  • Feather Stars
  • Chromids
  • Fusiliers
  • Titan Triggerfish
Barracuda Bommie
Location: Agincourt Reef 2

Maximum Depth: 22m

Visibility: 15 - 30m | Average: 20m

Site: Fantastic pinnacle with schools of barracuda circling the bommie.  Great fish life including lion fish. Sandy shallows covered in boulder corals also make this an ideal snorkel site.

Marine Life:
  • Barracuda
  • Dog Tooth Tuna
  • Fairy Basslets
  • Fusiliers
  • Drummers
  • Feather Stars
  • Goatfish
Horseshoe Reef
Location: Agincourt Reef 2

Maximum Depth: 20m

Visibility: 12 - 30m | Average: 20m

Site: When possible we drift dive along the northern edge of the reef. Huge schools of luminescent Blue Fusiliers hug the walls as Trevally and Red Bass patrol the edges.

Marine Life:
  • Blue Fusiliers
  • Mackerel
  • Trevally
  • Red Bass
  • Humphead Parrot Fish
  • Maori Wrasse
Turtle Bay
Location: Agincourt Reef 2

Maximum Depth: 22m

Visibility: 10 - 30m | Average: 20m

Site: Located at the northern end of Agincourt 2, this sheltered location is home to a large Loggerhead Turtle regularly seen during the summer months. The reef wall is decorated in hard and soft corals and a short swim brings you to the front of the reef, where many pelagic species such as Trevally, mackerel and sharks can be encountered.

Marine Life:
  • Sea Cucumbers
  • Parrotfish
  • White Tip Reef Sharks
  • Sweetlips
  • Giant Clams
  • Goatfish
  • Chromids
  • Fusiliers
West End
Location: Agincourt Reef 2

Maximum Depth: 15m

Visibility: 8 - 25m | Average: 15m

Site: A magical garden reef with frequent visits from a very large Maori Wrasse. A major plus for this site is that it has the largest swim through caves in the area.

Marine Life:
  • Blue Fusiliers
  • Trout
  • Potato Cod
  • Parrot Fish
  • Surgeon Fish
Nursery Bommie
Location: Agincourt Reef 2

Maximum Depth: 24m

Visibility: 12 - 30m | Average: 20m

Site: A stunning 24 metre Pinnacle surrounded by an amazing variety of marine life. Considered to be one of the best sites in the area.

Marine Life:
  • Sharks
  • Stingrays
  • Barracuda
  • Trevally
  • Drummers
  • Moray Eels
  • Snapper
  • Anthias
Izzy's Wall
Location: Agincourt Reef 2

Maximum Depth: 30m

Visibility: 12 - 30m | Average: 20m

Site: Wall and drive dive.

Marine Life:
  • Turtles
  • Sharks
  • Baby Whaler Sharks
  • Fusiliers
  • Anthias

Agincourt Reef 3

From sandy lagoons littered with coral pinnacles and an old fishing boat wreck at the aptly named “Wreck” site, to the thrill of diving and snorkelling along a reef wall with numerous small grottos at The Gap. Here’s a snapshot of some of the sites that Silversonic visits at Agincourt Reef 3.

Rating:

Novice - Intermediate

Visibility:

10 - 40 Metres

Depth:

5 - 30 Metres

The Gap
Location: Agincourt Reef 3

Maximum Depth: 12m

Visibility: 12 - 25m | Average: 15m

‍Site: Lagoon type gutter, close to the reef crest. Drift dive and snorkel often available along a fascinating reef wall withnumerous small grottos.

Marine Life:
  • Golden Goatfish
  • Large schools of Sweetlips
  • Groper
  • Boulder
  • Staghorn coral beds
Wreck Site
Location: Agincourt Reef 3

Maximum Depth: 24m

Visibility: 12 - 40m | Average: 20m

Site: Sandy lagoon littered with imposing 12 metre pinnacles. In the shallows lie the remains of a Taiwanese fishing vessel.

Marine Life:
  • Red Bass
  • Spangled Emperor
  • Rays
  • Coral Trout
  • Whitetip Reef Sharks
  • Clownfish
  • Groper
Phil's Reef
Location: Agincourt Reef 3

Maximum Depth: 16m

Visibility: 10 - 30m | Average: 15m

Site: Stunning patch reef with a spectacular array of corals, huge plates providing perfect ambush grounds for a variety of Groper.

Marine Life:
  • White Tip Reef Sharks
  • Groper
  • Cuttlefish
  • Hussar Snapper
  • Blue Spot Lagoon Rays
  • Giant Clams
Stonehenge
Location: Agincourt Reef 3

Maximum Depth: 20m

Visibility: 10 - 30m | Average: 15m

Site: Stonehenge is rich in coral diversity and hasawesome swim throughs.

Marine Life:
  • Giant Clams
  • Clownfish
  • Cuttlefish
  • Fusiliers
  • Reef Sharks
Coronation Corner
Location: Agincourt Reef 3

Maximum Depth: 25m

Visibility: 12 - 40m | Average: 20m

Site: Located at the southern end of Agincourt Reef 3

Marine Life:
  • Sharks
  • Cuttlefish
  • Barracuda
  • Sweetlips
  • Fusiliers

Agincourt Reef 4

Located at the Northern end of the Agincourt reef chain, Agincourt Reef 4 showcases a rich tapestry of coral and marine diversity.

Experience the pretty garden site of the Three Sisters with its three prominent coral bommies to the stunning patch reef with swim-throughs at The Chapel. Here’s a snapshot of some of our Agincourt Reef 4 sites.

Rating:

Novice - Intermediate

Visibility:

10 - 40 Metres

Depth:

5 - 40 Metres

Harry's Bommie
Location: Agincourt Reef 4

Maximum Depth: 16m

Visibility: 10 - 30m | Average: 15m

Site: A stunning garden reef scattered around the pinnacles and patch reefs of Agincourt reef 4. A favourite amongst Dive Instructors and a site regularly visited by juvenile Grey Reef Whalers and occasionally Manta Rays.

Marine Life:
  • Sharks
  • Rays
  • Groper
  • Oceanic Sweetlips
  • Oceanic Trout
  • Moray Eels
  • Anthias
Three Sisters
Location: Agincourt Reef 4

Maximum Depth: 20m

Visibility: 15 - 30m | Average: 18m

Site: Pretty garden site with 3 prominent bommies, 50m from the mooring. The site is often visited by juvenile Grey Reef Whalers and huge schools of congregating fish.

Marine Life:
  • Grey Reef Whalers
  • White Tip Reef Sharks
  • Red Bars
  • Spangled Emperor
  • Fusiliers
  • Stingrays
The Chapel
Location: Agincourt Reef 4

Maximum Depth: 18m

Visibility: 10 - 35m | Average: 15m

Site: Located on Agincourt Reef 4, this stunning patch reef is home to a diverse array of corals including Plate, Boulder, Staghorn and Seafans, with several "Swim Throughs". Perfect habitat for Sea Anemones and their resident Clownfish.

Marine Life:
  • Grey Reef Whaler Sharks
  • Cuttlefish
  • Giant Clams
  • Clownfish
  • Turtles
  • Schools of Baitfish
Gary's Gut
Location: Agincourt Reef 4

Maximum Depth: 40m

Visibility: 12 - 40m | Average: 20m

Site: Terrific wall plunging from 5 - 40 metres. Great to just swim out and look back at the drop to get the sense of size. Look out for fan corals and sharks. this site offers a great contrast to others you will visit.

Marine Life:
  • Unicorn Fish
  • Unique Butterfly Species
  • Surf Parrotfish
  • White Tip Reef Sharks
  • Xenias (Soft Corals)
The Point
Location: Agincourt Reef 4

Maximum Depth: 25m

Visibility: 15 - 30m | Average: 20m

Site: Excellent site at the southern end of Agincourt reef 4 with magnificent coral cover. Large schools of Red Bass and Goldmann's Sweetlips around the point, with cruising barracuda schools and big eyed Trevally.

Marine Life:
  • Red Bass
  • Maori Wrasse
  • Big eyed Bream
  • Barracuda
  • Grey Reef Sharks
  • Trout
  • Fairy Basslets