OtaruHarbor
OTARU
OTARU HARBOR
Otaru Harbor is situated on the south shore of Ishikari Bay, and is positioned on the east side of a small, northward extending peninsula (Figure V-158).
The east side of the inner harbor is defined by a 1,684 yd (1,540 m) long, north breakwater; a detached 1,001 yd (915 m) long, center breakwater; and a south breakwater that is 892 yd (816 m) long (Figure V-159). A fourth; 290 yd (265 m) long, detached breakwater extending east-southeastward near the south end of the north breakwater protects the harbor entrance.
A fifth, 110 yd (101 m) long, detached breakwater extending east-southeastward near the south end of the center breakwater protects the relatively narrow passage between the center breakwater and the south breakwater. All breakwaters are approximately 6.5 ft (2 m) high.
The harbor is entered through the 219 yd (200 m) wide entrance which passes between the north and center breakwaters. Charted depths in the 547 yd (500 m) long channel leading from the harbor limit to the harbor entrance (Figure V-159) are 49 ft (15 m) or greater. Depths in the inner harbor vary significantly from location to location, with the shallower depths generally confined to the northwestern part of the harbor.
U. S. Navy ships are normally assigned to berths 1 and/or 2 of the 800 yd (732 m) long Katsunai Wharf, which is located in the southern part of the harbor. Charted depths from the harbor entrance to Katsunai Wharf are generally in the range of 33 to 49 ft (10 to 15 m). Depths alongside berths 1 and 2 at Katsunai Wharf were reported to be 24.6 to 39 ft (7.5 to 11.9 m) during a visit by a U. S. Navy ship (FICPAC, 1992). Harbor authorities at Otaru state that Amphibious Command ships of the Blue Ridge class (620 ft long, 19,290 tons) are the largest vessels that Katsunai Wharf can accommodate.
Although not likely, it is possible that U. S. Navy ships may be assigned to Wharf 3, berths 15, 16 and/or 17. According to local harbor authorities and a Japanese harbor chart promoting the use of Otaru Port, alongside depth at the three berths is 29.5 ft (9 m), but DMA Chart 96942 shows depths as shallow as 21 ft (6.4 m) close to berth 15. Japanese Maritime Self Defense Force (JMSDF) ships usually moor to Ironai Wharf, berth 1.
Charted depths from the harbor entrance to approximately 328 yd (300 m) from Wharf number 3 are in the range of 33 to 49 ft (10 to 15 m), but diminish to less than 33 ft (10 m) within 328 yd (300 m) of the wharf.
Otaru has two primary anchorages: a safety/quarantine anchorage outside the breakwaters at the position indicated an Figure V-159, and an anchorage in the inner harbor. The outer anchorage has a sand bottom of unspecified holding quality. The exact location of the inner harbor anchorage is not shown on available charts, but is reported to have a mud bottom with good holding. A Japanese harbor chart indicates a portion of the anchorage is in Section I of the harbor near the 20 meter depth contour shown on Figure V-159, and another is northeast of Katsunai Wharf in Section II of the harbor. Local authorities state that U. S. Navy ships will always be assigned berths at the wharves and not be required to use the anchorages.
The Japanese harbor chart also shows an anchorage for ships with dangerous cargo. As indicated on Figure V-159, it is located about 350 yd east of the north breakwater in depths of 33-36 ft (10-11 m) in Section III of the harbor.
Tidal range at the port is minimal, about 1.1 ft (34 cm). Local harbor authorities state that currents at Otaru are essentially non-existent and pose no problem to harbor operations.
Source: http://www.nrlmry.navy.mil/port_studies/thh-nc/japan/otaru/text/sect2.htm
