Cockermouth Island Reef (Mackay Islands)

Moderate risk: Strong tidal currents (up to 8m range)

Tides of up to 8 metres create strong currents through the lagoon channels, especially during outgoing tide. Snorkellers must be aware of tidal flow to avoid being swept away from the island.

Moderate risk: Remote location — no facilities or water

The island is accessible only by private boat or charter. There are no facilities, no drinking water, and no ranger station. Snorkellers must be fully self-sufficient.

Moderate risk: Strong tidal currents

Tides in this area can reach up to 8 metres, creating very strong currents through the lagoon channels, especially during incoming and outgoing tides.

Moderate risk: Marine stingers

Marine stingers (box jellyfish and Irukandji) are present in the warm waters of the Great Barrier Reef Marine Park. Year-round risk, peaking in warmer months.

Moderate risk: Outgoing tide current

Tidal range up to 8 metres creates strong currents, especially around the reef edges and lagoon entrance. Snorkellers should be aware of tide times and avoid being swept out of the lagoon.

Moderate risk: Extreme tidal range

Tides range up to 8 metres, causing rapid water movement through the lagoon channels. Snorkelers must time their entry with slack tide and avoid being swept out.

Moderate risk: Remote location

Remote island with no facilities, medical aid, or ranger presence. Emergencies require self-rescue or satellite communication.

Low risk: Marine stingers (jellyfish)

Marine stingers (including box jellyfish and Irukandji) are present in these tropical waters, particularly during the warmer months.

Low risk: Sharp exposed reef at low tide

The ancient Pleistocene reef and coral bommies are exposed at low tide and can be razor-sharp. Snorkellers should wear reef shoes and avoid standing on coral.

Low risk: Extreme sun exposure

Sun exposure is extreme in tropical Queensland waters. Limited shade on the island's open grassland areas.

Low risk: Remote location — no facilities

Remote island with no facilities, drinking water, or mobile reception. Self-sufficiency is essential.

Low risk: Remote isolation

The island is remote with no facilities, drinking water, or phone reception. Snorkellers must be fully self-sufficient and carry emergency communication.

Low risk: Shallow coral exposure at low tide

At low tide, large areas of the lagoon are very shallow (less than 1 m), exposing the ancient Pleistocene reef platform with sharp coral.

Low risk: Low tide exposure of reef

During low tide, large areas of the lagoon on the western side recede to expose an ancient Pleistocene reef. Snorkellers must be careful not to walk on exposed coral and avoid being stranded in the lagoon.

Low risk: Small reef sharks in lagoon

Small (under 2 feet) reef sharks such as epaulette sharks are commonly seen cruising the lagoon. They are harmless and will quickly swim away if approached, but swimmers should be aware and give them space.

Low risk: Exposed reef at low tide

The lagoon is very shallow at low tide, exposing ancient reef platforms. Snorkelers risk cuts and scrapes from sharp coral if not careful.

Low risk: Juvenile reef sharks

Small reef sharks (up to 2 ft) cruise the lagoon daily. While harmless and shy, they may startle inexperienced snorkelers.