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Practice Sheet No. 1, Heron Sound (invented, not for navigation) 34 41 22 38 29 18 27 44 12 21 19 N VAR 7°W (invented) Heron Sound Heron Point Tern Island Westfield Kittle Gannet Rock Fl W 4s 52ft 14M TR TANK SPIRE STACK Dbn 1 2 3 HS 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Border scale: nautical miles (1 nm = 10 ticks) PRACTICE SHEET No. 1 · HERON SOUNDInvented for practice · NOT FOR NAVIGATION · Plotroom 1510
Dividers: drag from one point to another on the chart

Start a drag on a charted object or buoy and it snaps to it. The readout gives the true bearing (and magnetic, 7°W) from where you start to where you are, and the distance in nautical miles.

Skill 5 · Set and driftProblem 143005

Your 1540 fix is not where the DR said: find the set and drift.

At 1510 your fix is 149°T, 1.3 nm from Gannet Rock daybeacon. You steer 043°T at 6.9 kn through the water. At 1540 a new fix puts you 079°T, 3.1 nm from Gannet Rock daybeacon.

Plot the 1540 DR, then find the current: set (the true direction the water moved you, from the DR to the fix) and drift (its speed in knots over the 30 minutes).

Tolerance: 4° and 0.15 kn.

Given
1510 fix149°T, 1.3 nm from Gannet Rock daybeacon
Course and speed043°T, 6.9 kn
1540 fix079°T, 3.1 nm from Gannet Rock daybeacon
°T
kn
New problem

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