• Brown/Yellow for CM93 charts (vector
charts)
• The current chart displays as a lighter
shade of its color, or if quilting is
active, the charts currently making up
the quilt are displayed in lighter shade.
TIDES AND CURRENTS
As a precaution, remember the following
about tides and current displays:
• Tide and Current predictions are not
available for all areas
• OpenCPN comes with a built-in tidal
data file, but can use any legacy IDX or
binary tcd files. Multiple tidal files can
be used at the same time.
• As with all predictions, the displayed
values are calculated using mathematical
models and actual tides and currents
will vary.
To enable the Tides and Currents display,
click the Toolbar tide stations or currents
buttons. Important: tide and current will
not be displayed unless the Toolbar buttons
are selected.
Available tide stations will show on
the chart as green graphs with a “T” logo;
the “T” becomes a yellow and blue vertical
bar when the scale is greater than
1:5000.000. The vertical bars contain a lot
of information at a glance.
Right click on either icon to see a tidal
graph. As you move the cursor along the
graph curve, the time and actual height of
the tide will be displayed. A heavy red line
displays the current time, and the time zone
appears above the date. If a waypoint, route
or a track is, or passes on top of a tidal icon,
a right click will show a context menu for
those features. To see the tidal graph, press
“Show Tide Information” at the bottom of
the menu.
The Tidal Dialog gives the name of
the station as well as the name of the Data
Source file. This is important when you
have multiple sources covering the same
area. Time and height for High Water and
Low Water are displayed in the upper right
part. The Yellow box, with the tidal rise
and time, follows the cursor when hovering
over the dialog. The time axis at the bottom
displays the time.
DISPLAYING CURRENTS
Available current stations will show on the
chart as orange diamonds. When zooming
in, arrows will appear pointing in the direction
of the set. Note that “current” here is
short for “Tidal Current,” and is the same
as the UK term “Tidal Stream.” Master current
stations are shown like this in all scales.
No direction is associate with these stations
but they can be queried, by a right click, for
the magnitude of the current.
An arrow indicates current direction
and strength – the bigger the arrow, the
more the current.
If a waypoint, route or a track is, or
passes on top of a current icon, a right
click will show the context menu for those
features. To see the current graph, press
“Show Current Information” at the bottom
of the menu. The Yellow box, (time,
speed and direction) follows the cursor
when hovering over the dialog. Note that
OpenCPN can only display “Reversing
Currents” found in restricted waterways
such as rivers and straights. The general
case with “Rotary Tidal Currents” is they
cannot be displayed with this interface, but
are available for some areas as GRIB files.
We will learn more about GRIB Weather
Plugin in the Navigation course.
MARKS AND ROUTES
Marks are the basic points that are used
for many things, such as creating routes,
marking fishing spots, good anchorages or
anything of interest. Once a mark is created
a focused right- click dialog becomes available,
when clicking on the mark.
There are a few ways to directly create
marks. Pressing “Enter” or “Space” creates
a mark at the boat’s position and “Ctr+M”
creates a mark at the cursor position.
Right-clicking and pressing “Drop Mark”
creates a mark at the position the cursor
was when clicked. Marks are created at the
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