DR Sailing

Question 1

What is DR sailing

Answer 1

determining a ship’s approximate position by applying from it’s last known position, a vector or series of consecutive vectors representing the run that has since been made, using only courses steered and distance run

Question 2

How can you get a fix

Answer 2

soundings, vertical and horizontal
angles, bearings, and ranges

Question 3

Heading (SH)

Answer 3

direction in which a vessel points at any instant, Ships Head

Question 4

Course (C)

Answer 4

direction in which a vessel is to be steered, or is being steered

Question 5

Speed (S)

Answer 5

engine ordered rate of travel

Question 6

How do you measure course made good and speed made

Answer 6

measured fix to fix

Question 7

How many LOPs do you need to get a fix

Answer 7

2

Question 8

What is a running fix

Answer 8

position determined by the intersection of two (or more) LOP’s established at different times

Question 9

Estimated position

Answer 9

The most probable position of a vessel based upon available information or information of questionable accuracy

Question 10

What is the most accurate LOP

Answer 10

observing two or more objects in a line or visual ranges

Question 11

What should you do if there is ambiguity in the LOP taken for a fix

Answer 11

assume vessel is in worse position possible and make recommendation accordingly

Question 12

If two LOPs are used how far apart should they be

Answer 12

90 degrees

Question 13

If three LOPs are used for a fix how far apart should they be

Answer 13

120 degrees

Question 14

What size chart should you plot your DR

Answer 14

Largest scale chart available

Question 15

In restricted waters how often do you get a fix

Answer 15

Every three minutes

Question 16

In less restricted waters how often do you get a fix

Answer 16

Every 15 minutes

Question 17

For how long can you use a LOP for a running fix

Answer 17

30 minutes or less

Question 18

What is the secret to success for dead reckoning

Answer 18

practice and neatness

Question 19

What do you need if you want to figure out when a light will be lost from site

Answer 19

computed visibility

Question 20

What is the maximum distance a light can be seem in the meteorological conditions in immediate vicinity

Answer 20

Computed visability

Question 21

What is nominal range

Answer 21

maximum distance a light can be seem in clear weather

Question 22

what does the light list have

Answer 22

information for lights and buoys in US

Question 23

What does list of lights have

Answer 23

information for lights and buoys in international/foreign waters

Question 23

What is the three minute rule

Answer 23

distance traveled in yards in three minutes
ships speed in knots x 100

Question 24

What is the 6 minute rule

Answer 24

distance traveled in miles in 6 minutes

Question 25

What is a paper computer

Answer 25

Logarithmic speed time distance scale

Question 26

What is a nautical slide ruler

Answer 26

inexpensive plastic device used for rapid solution for time speed distance problems

Question 27

Six rules for dr plotting

Answer 27

plotted hour on the hour
every course change
every speed change
every fix or running fix
if single line of position is obtained
new course line plotted for fix or running fix

Question 28

How many intervals will you extend a DR or course line

Answer 28

two fix intervals

Question 29

What is an EP considered

Answer 29

midway between a good running fix and a unsubstantiated DR position

Question 30

Dangers bearing ahead and to the left of the track are labeled? and the right?

Answer 30

NMT
NLT

Question 31

If you do not have a sextant what else can you use to get an angle

Answer 31

position finder

Question 32

How often do you check your gyro error

Answer 32

once daily

Question 33

What can a single LOP provide

Answer 33

Cannot provide position but can give useful negative information