Miscellaneous Questions Flashcards
A chart suitable for inshore navigation, for entering bays and harbours, would have a scale of:
1:50,000 to 1:150,000
A composite great cirlce route is not as short a distance as a great circle route, but it is sometimes used instead. Why?
It avoids high latitudes where ice may be found
A free gyroscope is said to have “three degrees of freedom”. From those listed, which is NOT one of these?
Latitude axis
A gyro compass on a high-speed craft often takes time to settle correctly when altering course. What causes this problem?
The change in the (large) value of the latitude course and speed error when altering course
A light giving 4 flashes, which has sectors showing two different colours, could have an abbreviated description:
Fl(4) WR 15s 15m 12.10M
A position line on a chart is defined as a line:
somewhere on which the observer is situated
After all the adjustments have been made of the sextant, any remaining error is called:
index error
All gyro compasses, when on the eqautor, should have:
no latitude error
Apart from ensuring navigational safety at anchorage, what should the OOW do?
Monitor the VHF for orders for the vessel
At sunrise and sunset, the effect of atmospheric refraction is to:
reduce he sun’s apparent vertical diameter
At the summer solstice, the altitude of the sun at noon to an observer at the pole would be?
23.5°
At the winter solstice, the sun will not rise at all higher latitudes than:
66.5°
Charted depths are always measured below:
chart datum
Curves on chart showing values of equal variation are called:
Isogonic
Damping in azimuth in a gyro compass produces:
a setting position exactly on the meridian
Damping in tilt in a gyro compass produces:
an error which varies with latitude
Distance on a chart is measured using:
latitude sacle
Fiber-optic compasses have advantages over conventional gyro compasses. From those listed, which is NOT one of those advantages?
They are more accurate
For a circumpolar star, which from those listed is NOT true?
The LHA of the star will always be less than 90°
Free gyroscopes are turned into gyro compasses by utilizing:
gravity
From those listed which should be the preferred method position fixing for greatest accuracy and certainly of position?
taking a radar and visual bearing
From those listed, the best and target to use for a radar bearing is:
an isolated feature
From those listed, the best and target to use for radar ranging is a:
cliff face
From those listed, which are “ soft iron” corrector?
The spheres