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Experimental Chart Support for Racing


WARNING: The Chart feature is EXPERIMENTAL at this time. It is for testing and evaluation ONLY. Do not rely on it's accuracy.

WARNING: The Chart feature is for Sailboat Racing support, NOT GENERAL NAVIGATION. As such, it does not display all possible objects found on charts.

WARNING: The Chart feature has options under 'Preferences' to 'de-clutter' the display. SET YOUR 'SAFE DEPTH IN METERS' properly when using features like 'Show Safe Soundings'! The default is 3 meters.

NOTE: Hubbard Software does not provide charts. The Chart feature currently supports charts from the U.S. NOAA set in 'S57 ENC' format. See the Chart documentation below for details on downloading and importing them.

AGREEMENT: By Accepting the use of the Chart feature, you accept all liability for errors and/or omissions in the data and code of the chart function. You also agree to use other Navigation resources (charts and Apps) for general safe navigation. You also AGREE TO ABIDE BY U.S. NOAA's terms and conditions for using their charts. These are found on the NOAA web site when downloading the charts.

REQUEST: As this feature is experimental, Hubbard Software would like your feedback on problems, suggestions, features, etc... Since RaceTac draws all objects, feedback on shapes, colors, sizes, etc... is also welcome. Use the 'Contact' form on this website. Please include your device type. Thank you!

Chart Feature Documentation

Chart Support: Charts for RaceTac currently supports U.S. NOAA Electronic Navigation Charts (ENCs).  These are provided by NOAA in the International Hydrographic Organization (IHO) standard S57.  In theory, any S57 standard chart should work, but others have not been tested.  The chart function will work without any charts loaded, but will only graph your known marks, and your boat location.  It will not know of any obstructions, land, depth areas, navigational aids, etc... without loading charts for your area.  S57 Charts are also known as 'Vector Charts', as opposed to 'Raster Charts'.  Raster charts are actually just pictures of charts, whereas Vector charts are really a database of objects with coordinates and attributes.  I chose Vector charts, and although they require much more code to support, they also allow for much more flexibility, such as interaction with screen objects as described below.  Also note that NOAA is in the process of updating all the databases for these charts.  So 'Raster' charts may not exactly agree with 'Vector' charts until that project is finished.  However, Vector S57 charts are the future.

Chart Downloading: You can get the charts to your device's 'Downloads' folder in any way you want.  NOAA Charts are available from their ENC Website found HERE.  You can access the NOAA site from you device browser, email them to yourself as attachments, or other methods.  These charts sets are provided as ZIP files.  Just save the zip file in a common folder like the downloads folder on your device.  An Import dialog described below will access them and import them into RaceTac.


There are a number of options available for controlling the chart behavior.  Select 'Preferences' from RaceTac's menu, then select 'Chart Settings' to get a screen where you can change the settings.

The Current Settings are:

Show All Marks: When on, all of the Marks you have in the current Venue will be shown.  When off, only those in the current course are shown.

Safe Depth in Meters: In order to eliminate clutter, some options can hide chart objects if they are deeper than this setting.  The default is 3 meters.  So for example, a wreck may not be shown if deeper than this setting.  Also, Soundings can be hidden if deeper than this.

Show Safe Soundings: When on, ALL Soundings (depth indicators) are shown.   Those below the safe depth as well as shallow ones.  When off, only the soundings shallower than the safe depth are shown.  This is also true for coloring 'Depth Areas' such as those around the shore or a shoal area.  This helps un-clutter the display.

Gate Course Lines: This pops up a choice for how the Course Lines are drawn when 'Gates' are involved.  If a Mark is actually a 'Gate', such as a start or finish line, you can choose to have the course line drawn to and/or from the middle of the lines, or to and from the closest end points.  REMEMBER:  The closest end isn't always the 'favored end', depending on wind conditions and the tactical situation!

Chart and Boat Orientation: You can choose to have the chart locked, North up, and the boat icon moves,  or the boat can be fixed in the center, and the chart moves around it with North up (Version 1.61 and above), and in 1.62 and above, the Boat can be centered and always up, and the chart moves and rotates around it.

Depth Unit: Not under the Chart Settings, but up under the 'Units of Measure' preferences, you will now find a Depth Unit.  You can choose from Feet, Meters, or Fathoms.  The default is meters.

Chart Management

Chart Management: In the RaceTac Menu, you will see an entry for 'Chart Management'.  Selecting it will display a sub-menu.  Selecting 'Charts' will show a list of currently imported charts, and several buttons as shown.  You can DELETE a chart by tapping the selection box on one or more charts and then hitting the DELETE button.  This deletes the imported data, but will not remove the ZIP file you used for importing the chart.

Importing: Just tap the IMPORT button to get to a file dialog.  In that dialog, navigate to your download folder or other location, and tap the ZIP filename for the chart.  NOAA Charts are named after the 'Cell ID' for the area covered.  In the screenshot here, you see the 'Cell ID' as the name of each chart.  So the NOAA file would be something like 'US4NY1GM.zip' .

Chart Features and Behavior

Chart Display: You will recognize the basic nautical chart objects.  Lateral buoys like cans and nuns, obstructions like wrecks, rocks, pilings, etc..   Also depth contour lines, and shallow areas in a darker blue.  A few notes:

Obstructions: Rocks show as red asterisks.  In fact, obstructions are generally shown in red.  Wrecks show as the common 'fish bones' symbol.  A general obstructed area is an area with a red outline.  Most obstructions deeper than your 'Safe Depth' (see preferences) are not shown.

Navigational Aids (Government Marks): Cans are shown as the usual rectangles, nuns (conical) are shown in the usual shape.  Colors are as usually indicated.  Day Marks and Light Houses are shown as a rectangle with a contrasting cross through them, sort of to indicate the lattice structure.

Shore Lines: Regular shoreline is a brown line surrounding a land area.  However a man made structure such as a bulwarks, breakwater, docks, are drawn in black.

Depths: Soundings are light blue depths shown as the whole unit (as you selected in the preferences) and the decimal fraction to 1/10th shown as a digit that is smaller and to the right and below the whole unit.  There is a preference to not show soundings that are deeper than the safe depth you choose.  Depth contours are shown as light blue lines.  Depth Areas are only colored in if shallower than your 'Safe Depth'.

Areas: Unlike some charts, RaceTac does not differentiate different classes of land or sea areas.  So a marsh is just a shallow sea area, and will not be in a different color, or have the 'grass' symbol.  This app is for racing.  Land areas are also all one color.  No roads or land structures are drawn at present (Except daymarks and lights).  So no buildings, tanks, towers, etc...

Names: Navigational Aids are named with their 'short name' that is the one you are used to seeing.  Marks are labeled with the names from your list of marks in the current venue.

Racing Objects: Racing Marks for the current venue are shown as small circles with a black outline.  Marks in the course are orange, marks not in the current course are in yellow.  Marks that are ends of gates, such as my 'SF' buoy in the screenshot, and the 'CB (Committee Boat), are smaller circles in their color, with a line between them.

Course Lines are shown in orange with arrows from the start to the finish.  The current leg is shown in green.  If you have chosen to indicate a 'rounding side' (leave mark to port or starboard) the head of the arrow indicates the side to leave the mark on.  Red or Green.  If no preference is selected, it shows as blue.  Also, the line will be tilted slightly to the proper side.

Bearing Line: An optional red line from the boat to the current mark, so you can visually see your boat heading vs your bearing to the mark.  This obeys the 'Gate Line' options, so it will draw either to the middle of a gate or the closest end, as per your setting for gates.

Other data: Superimposed on the top area of the chart, partly transparent, are your current Speed over ground (SOG) and Velocity made good (VMG).  These are shown in units you chose in the preferences.  In this shot, they are N/A because my device did not have a GPS fix at the time I took the screenshot.

Buttons: From left to right, the buttons at the bottom are:  

- Zoom Out 30%.

- Backup to previous leg (Just like the 'Race Mode' displays where you can tap the marks at the top to advance or back up legs). 

- Options: In 1.70 and later this pops up a dialog with chart options, so you can change them right from the chart, rather than needing to go into the app 'Preferences'.

- Forward to next leg (if for example you are not using 'AutoRound').

- Zoom in 30%.

Touching: The screen will respond to the usual touch and drag, and also the usual 'pinch' with two fingers to zoom in or out.

Interaction: In 1.62 and above: You can tap a Mark or a Navigational Aid.  For Marks, you get options to set the location, set the rounding side, or edit the Mark info.  For NavAids you get options to COPY the Aid to your Marks list, or show additional details about the Aid.  NOTE: A COPY is made to your Marks list.  They are not linked together.  So editing your Mark will not change the Nav Aid.  Also, the name will be a letter corresponding to the color, and then the 'short' name as seen on the chart.  So a red "2" will be "R2".  Some NavAids do not have names.  For those, the name of the new Mark will be "NAV-" followed by the color letter, followed by a unique number starting at 1.  So "NAV-R1".  The next one, to prevent duplicates, if also red, would be "NAV-R2", etc... 

Behavior: Note that the display will change the leg colors automatically to show the current leg in blue if 'AutoRound' is selected in the preferences.

Multiple Charts: It is common to have charts of different scales loaded which overlap.  For example a large base map, and then a harbor area map.  RaceTac starts with the largest scale, and works down toward the highest resolution.  An interesting artifact of this is that some charts are not contiguous.  For example I have one that has 6 separate areas.  This can cause the display to look a bit like Swiss Cheese at times, with an odd triangle here or there.  This is normal with ENC Vector charts.