At 0726 you depart Lake Montauk with light 1...

Question 1 of 31048fork_c781552ffde34ec5b01

At 0726 you depart Lake Montauk with light 1 close aboard and set course 309° per standard magnetic compass at 6.7 knots. At 0818 your GPS position is LAT 41°07.1'N, LONG 72°02.6'W. What is the current?

Back

Question 1 of 31048

No Illustration

This question does not have an illustration

🔍 Key Concepts

• Course made good versus course steered: determine the vessel’s intended ground track from the departure and GPS fix, then compare it with the compass-directed course after applying compass corrections. • Compass conversions: use the attached deviation table at the applicable magnetic heading, together with the stated variation, to convert the standard-compass course to true. • Current vector: current is the difference between the vessel’s actual displacement over the elapsed time and its estimated movement through the water.

💭 Think About

• From the Lake Montauk departure at 0726 to the 0818 GPS fix, what are the elapsed time and the charted direction and distance of the actual track? • How does the plotted track compare with the true course you get after correctly applying deviation and variation to the stated standard-compass course? • What small direction and speed for the current would account for the difference between those two motions?

✅ Before You Answer

• Use the attached table’s deviation for the relevant magnetic heading; don’t treat deviation as variation or apply either correction with the wrong sign. • Convert 52 minutes to hours before using the 6.7-knot speed, and measure the displacement using the chart’s latitude scale. • For the current vector, distinguish direction toward which the current sets from the direction the vessel was steered; verify units in knots.