Meet the site
Blue Lagoon on the Agincourt complex is, according to Scuba IQ, largely inaccessible because of its tricky layout, and a rare treat that requires perfect conditions. It is not a site you can book; it is one the guides take divers to when everything lines up. Lagoon sites on the outer ribbon reefs are enclosed or semi-enclosed areas behind the reef crest where coral grows in sheltered water. Access is the challenge: moorings may be limited, entry channels shallow, and the tide and wind must allow a boat to reach them safely. When conditions permit, divers find calm, clear water, sandy floors and coral bommies growing up to the surface. Scuba IQ gives no further detail on the site's features or depths. Expect shallow water, sheltered conditions and a high density of coral and reef fish – the reward for the effort of getting there. Guides will brief the specific route and turnaround time. Visibility inside lagoons can be excellent on calm days, although it may reduce with tidal flow. Because conditions are critical, the dive may be cancelled or changed at short notice. Blue Lagoon suits divers who have done the regular Agincourt sites and want something unusual. It should not be confused with the Blue Lagoon on Opal Reef or at Lizard Island. If you are diving several days with a small-group operator such as Scuba IQ or Blue Dive, it is worth asking whether conditions might allow a visit – light winds, a neap tide and a boat small enough to reach the mooring are usually the prerequisites. Because the name is operator-specific, other boats may know the same area by a different name or not use it at all.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Blue Lagoon (Agincourt Reef) is recorded as Reef 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.
- 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 Blue Lagoon (Agincourt Reef) suitable for my certification?
The record lists 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 Blue Lagoon (Agincourt Reef) 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
Reef fish, hard corals, soft corals (details not published)
Location
A rarely accessible lagoon site on the Agincourt complex with a tricky layout, dived only in perfect conditions.
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
scubaiq.com.auRecord updated 26 Sept 2026. Source claims are being reviewed.