Chartwork practice for people who skipper their own boat
Plot it on paper. Check it to the degree.
Eight navigation skills, from compass conversions to a light rising over the horizon, worked on a real-feeling practice chart. Type your answer, see exactly how close you were, and read the worked solution, step by step.
Skills 1 to 4 free, as many problems as you like. Plot Pass $1.95/month or $19.50/year · Free during preview.
Worked on this page, by the same code that checks your answers
One fix, from the compass to the chart
This is problem 1015 of the two-bearing fix. Every problem on Plotroom is made and solved like this one.
i.Bearings taken
- Mill stack
- 210°M
- Westfield church spire
- 298°M
- Variation
- 7°W
ii.Converted and plotted
Magnetic to true with 7°W: T = M − 7. Mill stack: 210 − 7 = 203°T. Westfield church spire: 298 − 7 = 291°T.
The lines cross at 88° (a good cut is between 30° and 150°).
iii.The fix
154°T · 2.26 nm
bearing from Green can "3". Answers within 2° and 0.15 nm count as right; the worked solution shows how far off you were either way.
The skills
Eight skills, in the order a navigator learns them
Each problem is made from a number (its seed), so the same problem opens again from your Plot Log, and a worksheet prints the same every time.
| No. | Skill | What you work out | Plan |
|---|---|---|---|
| 1 | Compass conversions | True, variation, magnetic, deviation, compass: both directions. | Free |
| 2 | Time, speed, distance | Sixty D equals S T: find the one you are missing. | Free |
| 3 | Dead reckoning | Two legs from a fix: where does the DR put you? | Free |
| 4 | Two-bearing fix | Hand-bearing compass on two charted objects: plot the fix. | Free |
| 5 | Set and drift | DR against the fix you got: which way and how fast is the water moving? | Plot Pass |
| 6 | Course to steer | Allow for the current: heading, speed made good, minutes to the mark. | Plot Pass |
| 7 | Doubling the angle on the bow | Two bow angles and a stopwatch: distance off now and when abeam. | Plot Pass |
| 8 | Light rising | Height of eye, height of the light: when will it show over the horizon? | Plot Pass |
How a problem goes
Read it, plot it, check it, learn from it
Read the problem
Courses, bearings, times and speeds, given the way a logbook or a chartwork exam gives them.
Plot it
Drag on the chart to lay off a bearing and step off a distance: the dividers read true, magnetic and nautical miles as you go.
Check it
The server works the same problem from the same numbers and tells you how far off you were, against a stated tolerance.
See the working
Every step, with the numbers, and the answer drawn on the chart. Then the next problem, or the same one again.
Rate card
Free to practise. A Pass for the rest of the chart table.
Free
$0
- Skills 1 to 4, unlimited problems
- Worked solutions and the chart tool
- A Plot Log of 100 attempts
Plot Pass
$1.95 a month · $19.50 a year
- Skills 5 to 8: set and drift, course to steer, doubling the angle, light rising
- Printable worksheets with answer keys
- A Plot Log of 5,000 attempts and CSV export
Checkout is not switched on yet. Until it is, everything above is open to everyone and nothing is charged. Pricing details