Several prominent landmarks mark the eastern seaward approaches to Pearl Harbor and Honolulu (Figure 2). Makapuu Head, located on Makapuu Point, the eastern extremity of Oahu, is a bold, barren, rocky headland 647 ft (197 m) high that is the landfall for vessels inbound from the mainland United States. Koko Crater, a sharp, brown, 1,204 ft (367 m) high cone is located 2.6 nmi southwest of Makapuu Head. Koko Head, located 4 nmi southwest of Makapuu Head, is a bold, 640 ft (195 m) high promontory with a steep seaward side. Diamond Head, the most widely known landmark on Oahu, is an extinct, 761 ft (232 m) high crater located nine nmi southwest of Makapuu Head, and about 9.5 nmi southeast of Pearl Harbor (U. S. Department of Commerce, 1992).
Seaward approaches from the west offer less dramatic landmarks. The coastline between Kaena Point and Barbers Point consists mainly of alternating ledges of rock and stretches of white sand with spurs of the Waianae Mountains extending to most of the points. Between the spurs and ridges are heavily wooded valleys that contrast with the rocky and bare mountains (U. S. Department of Commerce, 1992).
The following extract from U. S. Coast Pilot 7 (U. S. Department of Commerce, 1992). is relevant:
"Pearl Harbor, is a Defensive Sea Area established by Executive Order No. 8143 of May 26, 1939. The order states in part:
The area of water in Pearl Harbor, Island of Oahu Territory of Hawaii, lying between extreme high-water mark and the sea, and in and about the entrance channel to said harbor, with an area bounded by the extreme high-water mark, a line bearing S from the SW comer of Puuloa Naval Reservation, a line bearing S from Ahua Point, and a line bearing W from a point 3 miles due S from Ahua Point, has been established as a defensive sea area for purposes of national defense, and no persons (other than persons on public vessels of the United States) are permitted to enter this defensive sea area, and no vessels or other craft (other than public vessels of the United States) are permitted to navigate in this area, except by authority of the Secretary of the Navy.
Permission to enter Pearl Harbor must be obtained in advance from Commander, Naval Base, Pearl Harbor, Hawaii 96860."
Although Pearl Harbor is located in a low, flat plain, many features exist that are identifiable from its seaward approaches. The dome-shaped Ala Moana Building (21°17'34.3"N 157°50'35.0"W) in Honolulu is conspicuous. Blue lights are shown from the 315 ft high tower. Other features are listed in Fleet Guide Pearl Harbor, Defense Mapping Agency Hydrographic/Topographic Center (DMAHTC) Publication 941, Chapter 7. The Pearl Harbor Fleet Guide and DMAHTC Chart 19336 list an unmarked channel approach point (Papa Hotel) as being located at 21°16'06"N, 157°56'23"W (Figure 4). United States Coast Pilot 7 lists Papa Hotel as being located at 21°16'17"N 157°56'33"W, approximately 500 yd northwest of the Fleet Guide's position. The Pearl Harbor Entrance Channel commences some 4,000 yd from "Papa Hotel" on a bearing of 333º36'. The entrance channel is marked by lighted and unlighted buoys and a lighted range (U. S. Department of Commerce 1992). With an approximate width of 350 yd, the channel has an initial project depth of 49.9 ft (15.2 m) near the center and 45 ft (13.7 m) on either side of the central 100 yd wide main channel. The central channel project depth decreases to 45 ft (13.7 m) approximately one nmi north of the channel entrance. The project depths on either side of the central channel decrease to 40 ft (12.2 m) at the same location. The same depths are maintained in the Main Channel to a point adjacent to Dry Docks 1 and 2 (Figure 5). Channel depths within Pearl Harbor vary by location, and should be verified with the Pearl Harbor Port Operations Office.
Pearl Harbor is fan shaped with an entrance width of 400 yd (366 m) (Figures 3 and 5). Extending inland some 5 nmi, the main basin is divided by two peninsulas and an island into four smaller basins: West Loch, Middle Loch, East Loch, and Southeast Loch (Figures 3 and 5). Most of Pearl Harbor's facilities are located on East Loch and Southeast Loch. Middle Loch is used primarily as a Reserve Fleet Anchorage. The Naval Magazine maintains berths at the approximate mid-point of West Loch, but the upper half of the loch is too shallow for deep draft vessels. Three additional, smaller lochs, Quarry Loch, Merry Loch and Magazine Loch, are located adjacent to Southeast Loch.
Plans in progress during a 1994 port visit include a causeway to be built between the northeast point of Ford Island and the eastern shore of Pearl Harbor. The target completion date was not known at the time of the visit. Construction of the causeway will impact ship movement between East Loch and the South Channel.
The mean tidal range on the coast from Honolulu to Barbers Point is approximately 1.9 ft with an extreme range of 2.3 ft under usual conditions. According to U.S. Army Corps of Engineers (1980), the lowest tide on record is -1.15 ft and the highest is +3.1 ft. All of the preceding heights use a zero reference of mean lower low water.
As stated in the DMAHTC Publication Fleet Guide Pearl Harbor, ocean currents in the vicinity of the Hawaiian Islands are variable. The prevailing currents off Pearl Harbor and Honolulu set westerly, and are generally influenced by the speed and direction of the wind. There have been reports of strong northeast currents setting against the prevailing trade winds. The northernmost of two cyclonic eddies that are observed during the summer months in the lee of the Hawaiian Islands is centered south of Oahu. As stated in Fleet Guide Pearl Harbor. "In the vicinity of Honolulu, observed currents of about 1.5 to 3 kt setting westward have been associated with this eddy. Off Barbers Point to the westward of Pearl Harbor, currents up to 0.8 kt have been measured, and greater velocities have been reported. A dangerous westerly set may be experienced in the vicinity of the entrance of the Pearl Harbor Channel."
The Fleet Guide Further states "Low pressure systems passing in the vicinity of the Hawaiian Islands, particularly during the winter months, will cause southerly to westerly winds along the normally leeward shores of the islands. The winds may cause the currents off the southern coast to reverse and flow eastward." Tidal currents in the approaches to Pearl Harbor are usually semidiurnal, but the two flood and ebb currents per day are often unequal in speed and direction. About two nmi south-southwestward of the entrance to Pearl Harbor, currents have been observed to flood 060º and ebb 191º, with maximum strengths of 0.6 kt. Generally, tidal current velocity in the approaches is less than 0.3 kt (DMAHTC, 1994).
Due to lack of swinging room, there is only one anchorage within the confines of Pearl Harbor. It is an explosives anchorage located north of Ford Island in East Loch (Figure 5). Harbor pilots state that if a large vessel assigned to the anchorage requires more swinging room than the approximate 175 yd radius the anchorage allows, the anchorage is shifted to a position 200 to 300 yd southwest of the charted position.
Anchorage is available outside Pearl Harbor in 60 ft (18.3 m) of water adjacent to the "Reef Runway" of Honolulu International Airport. The approximate position is indicated by the letter "A" on Figure 4. As shown on the same figure, an explosives anchorage is located in the same general area near 21°17'20"N 157°55'15"W.
The current Fleet Guide for Pearl Harbor contains a listing of 99 berths inside the main channel entrance. Of those, 29 are assigned to the Naval Station, 32 to the Naval Shipyard, 19 to the Naval Supply Center, 14 to the Submarine Base, and five in West Loch to Naval Magazine. Specific data for each berth, such as berth length and alongside depth can be found in the Fleet Guide for Pearl Harbor. One significant change in the 1994 berth listing applies to Berth F5 just southeast of the USS Arizona Memorial monument on Ford Island. It was rebuilt and lengthened to 1,000 ft to accommodate the planned berthing of battleships at Pearl Harbor. The South Channel has been dredged to depths of 45 ft over much of the area between Ten Ten Dock and the USS Arizona Memorial to provide adequate clearance and turning room for the deep-drafted battleships. Because all of the battleships in the U.S. Navy inventory are now decommissioned, the pier is now designated for other uses.
According to local harbor authorities, there were 14 surface ships home ported at Pearl Harbor in 1994, with two more scheduled to arrive. In addition, there were 19 submarines home ported at Pearl Harbor, with five more scheduled to arrive. The best berths for large surface vessels were thought to be the Hotel berths and Kilo Piers 3 through 5 at the Naval Supply Center, the Naval Station's Foxtrot berths 12 and 13 on Merry Loch, and Bravo berths 22 through 26 at the Naval Shipyard. The best berths for small ships are Bravo 1 through Bravo 21 at the Naval Shipyard. Submarines are berthed in Magazine and Quarry Lochs.
Local harbor pilots state that the Naval Shipyard berths B15 through B21 and Naval Station berths M3 and M4 are in very good condition. Naval Shipyard berths B7, B8, B10, B11, B12 and B13 are weak due to toredo worm damage to wood pilings at and near the water level. Because of the worm damage, camels tend to crush the damaged pilings if a ship is forced on to her berth. As a result, ships requesting that a camel be placed inboard will normally be berthed outboard of another ship. Exceptions are granted only when required for specifically approved hull maintenance evolutions.
Vessels approaching Honolulu Harbor have many prominent landmarks and features to assist them (DMAHTC Charts 19367 and 19364, and U. S. Coast Pilot 7 published by the U. S. Department of Commerce) (Figure 6). Prominent features include Honolulu Harbor Entrance Light, which is situated 95 ft (29 m) above the water on an orange and white, banded, flagpole-type tower located on the southeast point of the entrance channel. Aloha Tower, a 193 ft (59 m) cream-colored clock tower on Pier 10, is one of the most conspicuous objects in the harbor. Other easily distinguishable marks include the tall, twin white office buildings 300 yd east of Aloha Tower that are particularly useful by day, the pineapple shaped 199 ft (61 m) water tank 0.7 nmi northwest of Aloha Tower, and Punchbowl Hill, a flat-topped, 500 ft (152 m) rise located one nmi inland, east of Aloha Tower. Of particular use at night are the horizontal blue lights of the Ala Moana Tower restaurant, 1.5 nmi east of the Honolulu Harbor Entrance. U. S. Coast Pilot 7 contains specific cautions regarding nighttime approaches to Honolulu Harbor since lights of one area are easily confused with lights of another, and groundings have occurred as a result of the confusion.
When approaching from seaward, the Honolulu Entrance Channel has controlling depths of 34 ft (10.4 m) in the left outside quarter, 40 ft (12.2 m) in the left inside quarter and 44 ft (13.4 m) in the right inside and outside quarters. Charted depths in much of Honolulu Harbor, including Kapalama Basin, commonly exceed 40 ft (12.2 m), but depths close to the piers are somewhat less. According to Pearl Harbor harbor pilots, Kalihi Channel at the Port of Honolulu is no longer used because two fixed bridges prevent deep draft vessels from entering Honolulu Harbor via the channel. Vertical clearance under the bridges is only 15 ft in the center of the spans.
Recommended anchorage for deep-draft Honolulu Harbor vessels, except during strong Kona winds and within 600 yd of the underwater sewer outfall lines extending seaward from Sand Island, is on a sand and coral bottom in 72 ft (22 m) of water in Mamala Bay between the seaward ends of Kalihi and Honolulu Channels. The approximate position is indicated by the letter B on Figure 4. Anchorage in the harbor basins is not practical because of the lack of swinging room. A designated explosives anchorage is located 1.3 nmi west of the seaward entrance to Kalihi Channel (Figure 4). Anchorage regulations may be obtained from the Office of the Commander, 14th Coast Guard District in Honolulu. Special restricted anchorages lie in waters adjacent to the east side of Barbers Point. Specific guidelines regarding their use can be found in the current issue of Port Series No. 50, The Ports of Hawaii (Honolulu, Hilo, Kawailiae, Kahului, Nawiliwili, and Port Allen), published by the U. S. Army Corps of Engineers.
The Port of Honolulu has over 60 piers and wharves. Of these, some 27 are deep draft facilities. A complete description of the facilities is contained in the U. S. Army Corps of Engineers' Port Series No. 50.
Waterfront wharf facilities for deep draft vessels are located along the sides of the Main and Kapalama Basins, the connecting channel, and the east side of the Honolulu Channel entrance to the port (Figure 6). The port's major container handling facilities are located on Sand Island along the south side of Kapalama Basin. Sand Island is government owned. It borders the seaward side of Honolulu Harbor. It was formed mostly from harbor dredging spoils.
Alongside depths in Honolulu Harbor range from 16 to 40 ft (4.9 to 12.2 m) with 30 to 35 ft (9 to 10.7 m) predominating. Deck heights vary from 6 to 8 ft (1.8 to 2.4 m). Due to the close proximity of Pearl Harbor, the Port of Honolulu facilities are not generally used by U. S. Navy vessels. Two U. S. Coast Guard cutters, three buoy tenders and two patrol craft are based at the U. S. Coast Guard Station on the northeast side of Sand Island. In addition to the Coast Guard complement, the U. S. Army has two vessels assigned to Sand Island.