Plotroom

PREVIEWFree during preview: checkout has not opened, so skills 5 to 8, worksheets and CSV cost nothing yet. Price when it opens: Plot Pass $1.95/month or $19.50/year.

Plot Log
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 1600
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 617006

Your 1635 fix is not where the DR said: find the set and drift.

At 1600 your fix is 202°T, 2.2 nm from Gannet Rock daybeacon. You steer 309°T at 6.4 kn through the water. At 1635 a new fix puts you 239°T, 2.5 nm from Tern Island tower.

Plot the 1635 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 35 minutes).

Tolerance: 4° and 0.15 kn.

Given
1600 fix202°T, 2.2 nm from Gannet Rock daybeacon
Course and speed309°T, 6.4 kn
1635 fix239°T, 2.5 nm from Tern Island tower
°T
kn
New problem

Plot Pass skill. Plot Pass $1.95/month or $19.50/year · Free during preview: all eight skills, worksheets with answer keys, a 5,000-attempt Plot Log and CSV.