Chartwork and navigation math trainer

ASA 101 is not a coastal navigation course, but a new skipper should understand nautical miles, knots, ETA, buoyage, safe water, and anchor-scope math before leaving familiar waters.

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Speed, distance, time

Knots are nautical miles per hour. Fill any two values and calculate the third.

3.2 nm at 4.8 kt takes 40 minutes.

Bearing helper

Use reciprocal bearings for return courses, ranges, and simple anchor-drag checks.

045 reciprocal is 225.

Anchor scope

Scope is rode length compared with total bow-to-bottom height. Add water depth, bow height, and expected tide rise.

10 + 3 + 2 = 15 ft. At 5:1, pay out about 75 ft of rode.

Current set and drift

Use this to see why current changes course over ground. It is simplified for training; real navigation needs a current table, chart, and local margin.

A 1 kt current for 45 min sets you about 0.75 nm in the current direction.

Mini chart drill

G3 R6 RW shoal 4 ft returning from sea 61114

This is a simplified training sketch, not a chart for navigation. Use real, current charts and local knowledge on the water.

NOAA Chart No. 1 symbol scavenger

Identify beginner-critical chart cues: soundings, hazards, cables, restricted areas, anchorages, light characteristics, and chart-note warnings. This is a training sketch based on Chart No. 1 categories, not a real chart.

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Start the symbol lab, then click the chart clue that answers the prompt.

Visual route-planning challenge

Pick the safest beginner track from the chart sketch. The goal is not a perfect navigator's plot; it is building the habit of checking depths, aids, current, commercial traffic, and escape room before drawing a straight GPS line.

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Saved chartwork drill

Run short navigation-math and chart-reading sessions. Scores and weak topics stay in this browser and feed readiness, progress backup, and final review.

Beginner chart-reading checklist

ItemWhat to checkWhy it matters
ScaleHow much area the chart coversA harbor chart shows hazards a small-scale coast chart may hide.
SoundingsDepth units, contour lines, drying areasYour keel needs margin after tide, waves, and error.
AidsRed nuns, green cans, preferred-channel marks, lightsThey only make sense when you know direction of buoyage.
HazardsRocks, shoals, cables, restricted areas, wrecksDo not route over danger just because the GPS line is straight.
Weather and tideWind direction, current, tide rise/fallNavigation decisions change when wind and current oppose each other.

Sources

Study aids to navigationPractice anchoringPlay rules game