Friday, April 25, 2008

Sidereal Compass (Traditional Navigation in the Western Pacific)

After learning the compass points, a student of navigation is taught all their reciprocals. The reciprocal of the rising of Vega in the northeast, for example, is the setting of Antares in the southwest. For every reciprocal pair a student must then learn what other reciprocal pair lies at a right angle to it. A compass star on the beam can serve as a guide when the star on which one's course is set is not visible.

A feel for the angular distances from one to another of all the compass points enables a navigator to maintain his course at the appropriate angle to any visible compass star or any other visible star known to rise and set at about the same place as a compass star. To be able to use the stars this way is essential, the navigator shifting from one to another as they rise and set in the course of a night. When no stars are visible, as in daylight or in overcast at night, a navigator still orients himself with reference to the star compass. Knowing the compass direction of wind and ocean swell, he can keep track of where he is headed.

Sailing Direction - All sailing directions are kept in relation to the sidereal compass, as are the relative locations of all places of interest, including such numerous seamarks as reefs, shoals, and marine life. To memorize this large body of information the Carolinians have developed various exercises.

"Island Looking" is the name of the most important exercise. With it, navigators and their pupils rehearse their knowledge of where islands are located in relation to one another. One takes an island and then goes around the compass naming the places that lie in each direction from that island. Then one takes another island and does the same. As they sit around the boathouse in the evening, older men quiz the younger men and one another. In reciting "Island Looking," a beginner gives the name of the nearest island that lies in a given compass direction from the hub island. As he goes around the compass, if no island lies in a particular direction, he so indicates. Later, the student learns to include reefs and shoals and, finally, living seamarks, filling most of the compass directions from each island. The sidereal compass here shows the places named on the compass directions as one looks out from Woleai Atoll.

Another exercise, "Sea Knowing," involves learning the names of all the sealanes, called "roads," between the various islands and reefs. To speak of sailing on the "Sea of Beads" is to indicate travel between Woleai and Eauripik on the star course between "Rising of Fishtail" (in Cassiopeia) and "Setting of Two Eyes" (Shaula in Scorpio). Referring only to the names of sealanes, those in the know can tell one another where they have been traveling and leave the untutored in the dark.

The exercise called "Sea Brothers" groups sealanes that lie on the same star compass coordinates. Thus on the course from "Rising of Fishtail" to "Setting of Two Eyes" lie the several sealanes that connect the islands of Pisaras and Pulusuk, Pikelot and Satawal, West Fayu and Lamotrek, Gaferut and Woleai, and Woleai and Eauripik. A navigator may forget the sailing directions from Woleai to Eauripik but remember that the Woleai-Eauripik sealane is "brother" to the West Fayu-Lamotrek sealane. His remembering the star coordinates for the latter allows him to retrieve the forgotten coordinates.