On 15 November your 1030 ZT DR position is...

On 15 November your 1030 ZT DR position is...

Question 1 of 2707066636eea28f7522a1c51aaed

On 15 November your 1030 ZT DR position is LAT 19°41'S, LONG 41°37'W. You are on course 239°T, speed 22 knots. Determine your 1200 position using the following observations of the Sun.

Question 1 of 27070

Q

On 15 November your 1030 ZT DR position is LAT 19°41'S, LONG 41°37'W. You are on course 239°T, speed 22 knots. Determine your 1200 position using the following observations of the Sun.

🔍 Key Concepts

• Convert the run from 1030 to 1200 at 22 knots into distance in nautical miles using $\text{Distance} = \text{Speed} \times \text{Time}$ • Use the course of 239°T to break the run into changes of latitude and longitude (meridional parts or plane sailing, depending on your method) • Remember that at 19°–20°S, one minute of longitude is less than one nautical mile; you must apply the cosine of the latitude to find the change in longitude

💭 Think About

• From 1030 to 1200, how many hours is the run, and what is the total distance steamed at 22 knots? • On a course of 239°T in the Southern Hemisphere and Western longitude, will your latitude increase or decrease, and will your longitude increase or decrease? • Once you compute the new latitude from the run, what change in longitude corresponds to the east–west component of your track at that latitude?

✅ Before You Answer

• Be sure your time interval from 1030 to 1200 is expressed in hours (including fractions) before multiplying by 22 knots • Check that your signs for changes (N vs S, E vs W) match the direction of travel on 239°T • Verify your longitude change uses the correct mid-latitude (or DR latitude) when applying the cosine to convert between departure and difference of longitude