| 摘要 |
A nautical calculator for determining magnetic course/bearing, true course/bearing, compass course/bearing, variation, deviation and relative bearing of a boat. The nautical calculator comprises a base plate, a rotatable disc and a transparent marker in which the base plate has a first end, a second end and a first scale. The first scale has graduations inscribed in an arc wherein the peak of the arc corresponds to the ship's lubber line. The disc comprises a central axis, an outer circumference and a second scale. The disc is connected to the base plate at its central axis by a connecting pin, screw or the like. The second scale has graduations form 0.degree. to 360.degree. located along the outer circumference of the disc and is juxtaposed to the first scale on the base plate. The base plate and disc can be rotated with respect to each other so that the graduations on the second scale are capable of being aligned with the graduations on the first scale. In a preferred aspect, the disc is rotatable connected at the central axis of the disc to the base plate so that the disc is rotatable about the base plate while the base plate is stationary. In an embodiment of the marine nautical calculator, the disc is stationary while the base plate rotates about the central axis. A transparent marker may be provided comprising an outer end, an inner end, and an axial line inscribed thereon which extends from the inner end to the outer end. A sliding plate may be provided having a circular configuration inscribed thereon. The circular configuration having a centre, a wind direction scale and a wind speed scale.
|
