Apra Harbor, also called Port Apra,^[1] is a deep-water port on the western side of the United States territory of Guam. It is considered one of the best natural ports in the Pacific Ocean.^[2] The harbor is bounded by Cabras Island and the Glass Breakwater to the north and the Orote Peninsula in the south. Naval Base Guam and the Port of Guam are the two major users of the harbor. It is also a popular recreation area for boaters, surfers, scuba divers, and other recreationalists.^[3]

The geography of Apra Harbor has been extensively modified from its pre-historical state by humans. The entrance to the harbor is flanked by Point Udall, formerly Orote Point, to the south and Spanish Rocks at the tip of the Glass Breakwater. The Glass Breakwater, built on top of Calalan Bank and the fringing Luminao Reef, connects to Cabras Island, the location of the Port of Guam, which handles more than 90% of civilian cargo imported to Guam. Inland areas in the villages of Piti and Santa Rita form the eastern boundary of the harbor. There are two small artificial peninsulas jutting into the eastern end of the harbor. The northernmost is named Drydock Island, the tip of which is a military reservation with wharves for fueling ships. South of Drydock Island is Sasa Bay, one of five marine preserves created by the Government of Guam. The southern boundary of Sasa Bay is formed by Polaris Point, a geographically separate part of Naval Base Guam that is the homeport of Submarine Squadron 15.^[4] Polaris Point and the Orote Peninsula form the entrance to Inner Apra Harbor, a military restricted area. The Orote Peninsula holds the main part of Naval Base Guam and is approximately four miles to its tip at Point Udall. There are two named large coral formations roughly west of Sasa Bay in Outer Apra Harbor: Western Shoals and Jade Shoals.

Ten rivers flow into Apra Harbor: Atantano River, Sasa River, Aguada River, Big Guatali River, Aplacho River, Maggo River, Guatali River, Laghas River, Tenjo River and Paulana River.^[5]

Apra comes from the Chamorro word "apapa", meaning "low." Apapa is the original name of Cabras Island. The harbor offered rich fishing grounds and was home to many Chamorro villages.^[3]

During Spanish rule, the name of Saint Louis IX was added and the harbor was referred to as the port of San Luis de Apra. However, it was not a favored anchorage during the Spanish–Chamorro Wars of the late seventeenth century and resulting the early Spanish period, mainly because of the many reefs and coral heads. The Spanish preferred ports were Umatac and Hagåtña, resulting in Apra Harbor being used by foreigners seeking to avoid Spanish authority. The English pirate John Eaton is reported to have anchored at Apra Harbor in 1685 to trade provisions with Chamorros.^[3]

In the early 18th century, Spain's Council of the Indies grew increasingly concerned about competing navies threatening the Manila galleon trade and Spain's possessions in the Pacific.^[7] This was aggravated by an attack in 1721 by the English privateer John Clipperton upon a supply ship from Cavite anchored at Merizo.^[8] In 1734, Governor Francisco de Cárdenas Pacheco opened up new anchorages in Apra Harbor, and built three cannon batteries or forts to protect them.^[7] Fort San Luis was built in 1737 near Gab Gab^[9] and Fort Santiago was built at Orote Point to guard the entrance to the harbor.^[10] The third fort, Fort Santa Cruz, was built around 1800 atop a reef near the entrance to the harbor.^[3]

William Haswell, an officer on the first documented American visit to Guam in January 1802, wrote a description of Apra Harbor:^[11]

Apra Harbor currently has many users, the two major ones being Naval Base Guam and the Port of Guam. Since 2009, facilities on Naval Base Guam are supported by Joint Region Marianas. The largest tenant unit at Naval Base Guam is Submarine Squadron 15, which is supported by ship tender USS Frank Cable.^{[citation needed]} Coast Guard Station Apra Harbor is also located on Naval Base Guam property and has an area of responsibility including the Mariana Islands, Palau and the Federated States of Micronesia; it has three Sentinel-class cutters: Frederick Hatch, Myrtle Hazard, and Oliver Henry; and the Seagoing Buoy Tender USCGC Sequoia.^[29] Kilo Wharf, located on the Orote Peninsula near the mouth of the harbor, is the only U.S. deep water ammunition port in the Western Pacific and also allows emergency berthing by visiting aircraft carriers,^[30][31] such as during the 2020 COVID-19 outbreak aboard USS Theodore Roosevelt.^[32]

The Port of Guam handles over ninety percent of total imports to Guam. In FY2008, more than 2 million cargo revenue tons in 99,908 containers were handled, including for transshipment to nearby Western Pacific islands.^[33] Five cruise ships visit Guam annually, requiring a reconfiguring of port operations.^[34][35]

Marinas are located in the area known as Inner Cabras in Piti between Cabras and Drydock Island, just south of the Guam Power Authority plants. Aquaworld Marina and Harbor of Refuge are owned and operated by the Port, with slips leased to tenants.^[36] The area, collectively known as Cabras Marina, berths personal small watercraft, diving boats, tourist sightseeing boats, and an Atlantis Submarine, which visits a coral reef off Gab Gab on the Orote Peninsula.^{[citation needed]} The Marianas Yacht Club, located on the south shore of Drydock Island on Sasa Bay, provides mooring buoys for transPacific cruising yachts^[37]

In addition to shore berths, a total of 21 mooring buoys are located in the harbor. However, none is suitable for large vessel mooring during a typhoon, requiring craft to put out to sea for safety in extreme weather. One buoy is reserved for a Military Sealift Command strategic sealift ship.^[30]

Recreation

Harbor beaches on Naval property include Gab Gab Beach and San Luis Beach on the Orote Peninsula, and Fantasy Island on Polaris Point.^[38] Beaches on Cabras include Family Beach and Outhouse Beach.^[39] Port Authority Beach is located on the north shore of Drydock Island.^[40]

Apra Harbor hosts a robust coral reef community and many shipwrecks. There are many named scuba diving sites either within or immediately outside the harbor, including: Harley Reef; SMS Cormoran and Tokai Maru, allowing divers to touch wrecks from the two World Wars at the same time; Jade Shoals; Big Blue Reef; Middle Shoals; Western Shoals; Gab Gab; Finger Reef; American Tanker; Blue and White; Luminau; Blue Hole;^[41] Kizugawa Maru;^[42] and many others.

The outer shore of the Glass Breakwater is one of the most popular surfing spots on Guam, along with Talofofo Bay and Inarajan Bay.^[43][44]

Sasa Bay Marine Preserve

The Sasa Bay Marine Preserve, comprising waters and lands between Drydock Island and Polaris Point, is a recreational and ecological protected area with regulated fishing. Measuring 3.118 square kilometres (770 acres), it is one of five Marine Preserves created by the Government of Guam in 1997.^[45] The Preserve contains a mangrove swamp, is a foraging area for Hawksbill sea turtle and is habitat for several oyster and clam species. It also includes four or five patch reefs in its deeper waters.^[46]

Operations in Outer Apra Harbor are under the jurisdiction of The Port Authority of Guam and the United States Coast Guard. Vessels entering, leaving, or shifting berth in Apra Harbor are required to give 24 hours notice to the Port Authority of Guam Port Control Harbor Master and the U.S. Coast Guard Captain of the Port. Inner Apra Harbor is a restricted area that is marked by two uncharted buoys. Operations in Inner Apra Harbor are under the jurisdiction of the U.S. Navy Port Control Harbormaster.^[47]

• Port Authority of Guam
• U.S. Naval Base Guam
• Photos of harbor clearance and construction, pages 53—69

13°27′12″N 144°39′12.56″E / 13.45333°N 144.6534889°E / 13.45333; 144.6534889