Meet the site
Gary's Gut is the deepest site on the Agincourt Reef No. 4 roster, a terrific wall plunging from 5 to 40 m, according to Silverseries and Poseidon. The site notes suggest swimming out from the wall to take in the drop – advice that captures the dive's main appeal, which is scale. After the gardens and bommies elsewhere on Agincourt, Gary's Gut offers a great contrast. The wall is steep and in places vertical, cut by gullies and overhangs. It is decorated with gorgonian fan corals and xenia soft corals that pulse gently in the current, as well as whip corals and sponges. The fish life includes unicornfish in schools off the wall, surf parrotfish on the reef crest, several species of butterflyfish, and whitetip reef sharks resting on ledges or cruising along the face. The depth available means the dive must be planned carefully. Open water divers should stay at 18 m or shallower, which still gives a spectacular view down the wall into the blue, while advanced divers can go a little deeper to see the larger fans. Because the wall offers no natural floor, buoyancy control and depth discipline are essential, and guides monitor depths closely. Visibility averages around 20 m and can reach 40 m, which lets you appreciate the full drop. The site is exposed to current at times, which feeds the fans and soft corals but can require some effort on the swim back to the mooring. Gary's Gut is ideal for Advanced Open Water divers or those wanting a taste of genuine outer-reef wall diving. Photographers will find large fans for wide-angle compositions, and divers looking for the sense of hanging over the abyss will find it here.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Gary's Gut (Agincourt Reef 4) is recorded as Wall in Port Douglas. The listed access is boat (day trip). 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.
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 Gary's Gut (Agincourt Reef 4) suitable for my certification?
The record lists Deep/Advanced + experience. 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 Gary's Gut (Agincourt Reef 4) 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
Unicornfish, surf parrotfish, butterflyfish (several species), whitetip reef sharks, gorgonian fans, xenia soft corals, whip corals, sponges
Location
A wall on Agincourt Reef No. 4 that plunges from 5 m to 40 m, decorated with fan corals and soft corals.
Facilities nearby
Departs Crystalbrook Superyacht Marina, Wharf Street, Port Douglas – car parking, toilets, cafes and restaurants at the marina; dive shops in town for gear hire and air
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
silverseries.com.auposeidon-cruises.com.auRecord updated 27 Sept 2026. Source claims are being reviewed.