Michaelmas And Upolu Cays National Park And Their Reefs

Michaelmas Cay
Michaelmas Cay

Michaelmas and Upolu Cays National Park sits within the Great Barrier Reef some 35 kilometres from Cairns, and The State of Queensland (Department of National Parks, Recreation, Sport and Racing) manages the parks.

While the Great Barrier Reef comprises over twenty-nine thousand reefs and has over 900 islands, these two Cays and reefs stand out from the rest.

The Great Barrier Reef park islands are continental islands (landmass) or Coral Cay. A few of the islands in this area of the park are Cays.

A coral Cay develops at a point where a current slows down over a reef and drops sediment.

This will continue until the sediment builds to a point where the current breaks in waves over the new shoreline.

Michaelmas Cay is moving north at the rate of about one meter a year.

In 1929, a borehole was drilled in the middle of the Cay to determine the underlining structure. The drilling revealed only a little depth of surface material before reaching the old reef.

They drilled into the reef 115 meters down before finding the sandy bottom. That borehole is no longer on the Cay but can be found on the reef south of the Cay.

Bird Sanctuary

Both Michaelmas and Upolu Cays are bird sanctuaries. Michaelmas Cay is the larger of the two and has developed some vegetation.

Twenty-four species of sea birds have been seen on this Cay, with nineteen known to nest and mate on this Cay.

It has been estimated that over 20,000 breeding pairs of sea birds can be found on the island at peak season.

The Cays are classified as sensitive areas, and visitors are limited. On Michaelmas Cay, visitors are only allowed from 9:30 am to 3:00 pm.

Only one boat a day and no more than 60 passengers are allowed except vessels holding a special permit. The protected zone extends outward for one nautical mile.

Access is allowed in one area where swimming and snorkelling are also allowed. Visitors can only access a small portion of the Cay. Most of it is roped off and restricted.

Upolu Cay, named after a ship grounded on its reef, is also a bird sanctuary. However, restrictions are not as tight.

Diving Michaelmas And Upolu Cays

Michaelmas Cay is well known as an excellent dive site. Many companies that bring visitors to the Cay visit the beach area for snorkelling and introductory diving.

However, most of the dive sites might be better identified as Michaelmas Reef instead of Michaelmas Cay.

The Cay, about 650 metres long and 180 metres wide at its widest point, sits on the southwest edge of the reef.

The Michaelmas Reef itself is about 11 kilometres long and over 1 kilometre wide at its widest point. Not including nearby Bommie and other reef outcrops.

Moorings

In addition to the two public moorings available, the reef has 18 private moorings maintained by eight different companies and a designated anchorage about mid-distance of the reef on the protected side.

The majority of the moorings are just west of the Cay, while others are to the North and South.

Quicksilver has 8 of the moorings, including one for a semi-submersible sub. Most of their other moorings are grouped near the Cay on the west side.

Suppose you subtract the moorings for the sub and its support facilities, about 14 dive sites around the Cay and reef. Between them, they offer a wide range of different underwater adventures.

Some sites have deeper water and offer such items as swim thoughts, coral gardens and Bommies.

Other moorings are near the main section of the reef, so divers and snorkelers can experience the flats of the reef in shallow waters.

All sites offer a wide range of marine life. A few of the moorings are on the east side of the reef. For example,160 meters east of Michaelmas Cay on the reef, MV Reef Encounter maintains a mooring.

Scuba diving

A small opening leads to what is almost like an underwater cave. Divers will find that they can travel in any direction from the boat and come to the rising coral.

Being the side that faces the deep, larger fish are found in this area, and green sea turtles frequently visit this site.

Upolu Cay is not visited as much as around Michaelmas reef.

Unlike Michaelmas Cay, Upolu Cay does not have vegetation, and the many sea birds only roost there. The Cay also will be underwater during some high tides. There is one public mooring and 11 private around the reef maintained by four companies.

These two cays offer a wide range of different dive sites with different attractions.

Nearby Reefs