BDOC Final
Table 3A Areas - Answer-Restricted, Pilot, Coastal, Open
Table 3A Distances from Land to Shore - Answer-< 2mi, 2-10mi, 10-30mi, > 30mi
Table 3A FOM's - Answer-<=2, <=4, <=6, <=7
Table 3A Max Fix Intervals - Answer-3min, 3-15min, 15-30min, 30min+
Buoy Shapes - Answer-Can, Nun, Pillar, Spar, Sphere
IALA A - Answer-Red Port, Green Starboard (Africa, Asia, Australia, Europe)
IALA B - Answer-Green Port, Red Starboard (America, Japan, Korea, Phillippines)
Compass Variation - Answer-error in the compass reading caused by the difference in location between
the magnetic north pole and the true north pole
, Compass Deviation - Answer-the error of a magnetic compass due to local magnetism (magnetic
properties of vessel)
US Navy Datum - Answer-WGS 84
3 Segments of GPS - Answer-Space, Control, User
Fourth satellite in GPS fix provides - Answer-Altitude
Advantages of Mercator Plot - Answer-Rhumb lines at straight lines, easy distance measuring, lat/longs
are straight lines with correct angular relationships
Disadvantages of mercator - Answer-great circles as curves, minor distortion at extreme latitudes
Gnomic Advantages - Answer-Great circles as straight lines, good for long distance voyages
gnomic disadvantages - Answer-Distance and direction cannot be measured directly (unusable as a
working chart); and
- Distortion of shape and scale increases as distance from the center of the projection (the point of
tangency) increases.
US Fleet Guides - Answer-Port information for USN bases
Nav Rules and Regs - Answer-Rules to prevent collisions at sea, published by USCG
Coast Pilots - Answer-INLAND waters, NOAA
Table 3A Areas - Answer-Restricted, Pilot, Coastal, Open
Table 3A Distances from Land to Shore - Answer-< 2mi, 2-10mi, 10-30mi, > 30mi
Table 3A FOM's - Answer-<=2, <=4, <=6, <=7
Table 3A Max Fix Intervals - Answer-3min, 3-15min, 15-30min, 30min+
Buoy Shapes - Answer-Can, Nun, Pillar, Spar, Sphere
IALA A - Answer-Red Port, Green Starboard (Africa, Asia, Australia, Europe)
IALA B - Answer-Green Port, Red Starboard (America, Japan, Korea, Phillippines)
Compass Variation - Answer-error in the compass reading caused by the difference in location between
the magnetic north pole and the true north pole
, Compass Deviation - Answer-the error of a magnetic compass due to local magnetism (magnetic
properties of vessel)
US Navy Datum - Answer-WGS 84
3 Segments of GPS - Answer-Space, Control, User
Fourth satellite in GPS fix provides - Answer-Altitude
Advantages of Mercator Plot - Answer-Rhumb lines at straight lines, easy distance measuring, lat/longs
are straight lines with correct angular relationships
Disadvantages of mercator - Answer-great circles as curves, minor distortion at extreme latitudes
Gnomic Advantages - Answer-Great circles as straight lines, good for long distance voyages
gnomic disadvantages - Answer-Distance and direction cannot be measured directly (unusable as a
working chart); and
- Distortion of shape and scale increases as distance from the center of the projection (the point of
tangency) increases.
US Fleet Guides - Answer-Port information for USN bases
Nav Rules and Regs - Answer-Rules to prevent collisions at sea, published by USCG
Coast Pilots - Answer-INLAND waters, NOAA
