Meet the site
Masthead Island is an undeveloped national park cay in the Capricorn Group, west of Heron Island and about 60 km from Gladstone. It is surrounded by a closed lagoon and reef system, supports Pisonia forest, and is a nesting site for seabirds (November-March) and shearwaters (October-May). Camping is permitted for small groups under QPWS permit, subject to seasonal closures. The fringing reef edge offers healthy hard coral gardens with turtles, reef sharks and rays. What makes the area particularly interesting for divers is nearby Polmaise Reef, where the Polmaise Bommies offer overhangs and swim-throughs in 16-20 m, and the remains of the 1879 steamer Tambaroora lie in 8 m. Masthead sees very few divers because there is no operator; visitors are private boat owners, campers and occasional liveaboards touring the Capricorn Group. That means the reef is quiet, but also that divers must be completely self-sufficient, carrying their own air, oxygen and communications. The island suits experienced divers with their own vessel who want to explore a less-visited part of the southern Great Barrier Reef, and camping groups with snorkelling in mind. Anyone visiting should respect the seabird nesting colonies and the closure periods. Masthead can be combined with Heron (where the resort is for guests only), Erskine and Wilson islands and North West Island in a multi-day boat trip through the Capricorn Group. Because the lagoon is enclosed, anchoring inside is not possible for most vessels; plan to anchor off the reef in the lee and use a tender for landings and shallow snorkelling.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Masthead Island Reef is recorded as Island in Heron Island & Capricorn Group. The listed access is boat (multi-day/liveaboard). Confirm the actual meeting point, route and permission to visit; a map pin does not establish any of these.
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 Masthead Island Reef 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 Masthead Island 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
Turtles, reef sharks, rays, hard coral gardens, reef fish, seabird colonies (above water)
Location
An undeveloped national park cay west of Heron Island, about 60 km north-east of Gladstone, surrounded by a closed lagoon and reef system; nearby Polmaise Reef holds the Polmaise Bommies and the Tambaroora wreck.
Facilities nearby
National park camping area (QPWS permit, small groups); no water, fuel or air fills.
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
marinelife.org.auprofessionaldiveservices.com.auen.wikipedia.orgRecord updated 27 Sept 2026. Source claims are being reviewed.