# Nautical chart symbol question **URL:** \ **Category:** Factual Questions\ **Created:** [October 6, 2016, 5:28pm UTC](https://boards.straightdope.com/t/nautical-chart-symbol-question/767784 "2016-10-06T17:28:17Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![MikeF](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@MikeF](https://boards.straightdope.com/u/MikeF)\ **Post date:** [October 6, 2016, 5:28pm UTC](https://boards.straightdope.com/t/nautical-chart-symbol-question/767784/1 "2016-10-06T17:28:17Z")
What does a small magenta circle with a dot in the center and numbered (0-11 on what I saw) arrows of varying lengths and unevenly spaced pointing outward from the circle mean? Bottom of page 41 here. [http://www.nauticalcharts.noaa.gov/mcd/chart1/ChartNo1.pdf](http://www.nauticalcharts.noaa.gov/mcd/chart1/ChartNo1.pdf) It says its a current diagram but how do you read it? ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [October 6, 2016, 6:49pm UTC](https://boards.straightdope.com/t/nautical-chart-symbol-question/767784/2 "2016-10-06T18:49:48Z")
Here is a good explanation: > **[Rotary Currents](http://davidburchnavigation.blogspot.com/2014/09/rotary-currents.html)** > > Most tidal currents we deal with on inland waters are reversing currents. That is, from slack water the current builds in the ebb direction ... Basically, if there are two arrows, it indicates a reversing current (due to tidal action); if there are a bunch of arrows, it indicates a rotary current. ---
**Author:** ![MikeF](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@MikeF](https://boards.straightdope.com/u/MikeF)\ **Post date:** [October 7, 2016, 2:57pm UTC](https://boards.straightdope.com/t/nautical-chart-symbol-question/767784/3 "2016-10-07T14:57:36Z")
Aha, that make sense. Its knowledge I’ll never need but my curiosity has been satisfied. Thanks.