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 kilometer from Cairns and The State of Queensland (Department of National Parks, Recreation, Sport and Racing) manages the parks. While the Great Barrier Reef is made up of over twenty-nine thousand reefs and has over 900 islands, these two Cays and reefs standout from the rest. The islands, in the Great Barrier Reef park, are either continental islands (land mass) or Coral Cay. 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 some of its sediment. This will continue until the sediment builds to a point where the current has to be deflected or that it breaks in waves over the new shore line. This is an ongoing process, in fact Michaelmas Cay is moving north at the rate of about one meter a year. In 1929, a bore hole was drilled in the middle of the Cay to determine the underlining structure. The drilling revealed that there was only a small depth of surface material before reaching the old reef. They drilled into the reef 115 meters down before finding the sandy bottom. That bore hole 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 found on the island and nineteen of those are known to nest and mate on the Cay. It has been estimated that over 20,000 breeding pairs 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 that 60 passengers are allowed except boats holding a special permit. The protected zone extends outward for one nautical mile. Access is allowed in one area where swimming and snorkeling is 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 that 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 of the companies that bring visitors to the Cay use the beach area for snorkeling and introduction diving. Most of the dive sites, however, might be better identified as Michaelmas Reef instead of Michaelmas Cay. The Cay, which is about 650 meters long and 180 meters wide at its widest point, sits on the south west edge of the reef. The Michaelmas Reef itself is about 11 kilometers long and over 1 kilometer wide at its widest point. This does not include nearby Brommie and other reef outcrops. In addition to the two public moorings available, the reef has 18 private moorings maintained by 8 different companies as well as a designated anchorage about mid-distance of the reef on the protected side. The majority of the moorings are just west of the Cay. Some of these moorings are located off the northern part of the reef while some are located on the south and east portion of the reef. Quicksilver has 8 of the moorings including one for a semi-submersible sub. Most of their other moorings are near group together near the Cay on the west side. If you subtract the moorings for the sub and its support facilities there are about 14 dive sites around the Cay and reef. Between them they offer a wide range of different underwater adventures. Some of the sites have deeper water and offer such items as swim thoughts, coral gardens and Brommies. Some of the moorings are near the main section of reef so diver 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. There is a small opening that leads to what is almost like an underwater cove. 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 it is common to see green turtles, which are known to visit the Cay.

The reefs around the Upolu Cay, are not visited as much as around Michaelmas reef. Unlike Michaelmas Cay, Upolu Cay does not have any 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.