Yes. While the Zero Line does make the process a little easier, it is not necessary to have a Zero Line to begin surveying an uncharted body of water.
Below are three examples of how a map can turn out using the 3 Zero Line options in AutoChart.
1. No Zero Line
- When there is no Zero Line available, AutoChart will still create a map of your survey. What you may notice is the edge of your map will appear jagged. This takes place because AutoChart doesn’t know where to “stop” the contours.
- The contours for this map would look similar to the image below. You will lose some shallow water detail with this method.
NOTE: Aerial Imagery can be displayed in AutoChart PC as the basemap. You can use this as a reference or as a simple way to create a custom Zero Line, as described later in this tutorial. You cannot transfer aerial imagery to the SD card to be displayed on the Humminbird fish finder.
To display Aerial imagery in AutoChart PC, start by right clicking over the lake you want to map and select the MAP HERE option.
- Next, select TOOLS > SETTING > BACKGROUND MAP
- It will open the option box below. The default will be set to LakeMaster. Choose ONLINE MAPS, select your map choice from the dropdown menu and click ok. In this case, we used MapQuest Open Aerial.
- Finally, you need to go into the MAP tab > OBJECTS and Select BACKGROUND MAP similar to the image below. Aerial photos will now be the default background map in AutoChart PC.
2. LakeMaster Zero Line
- The LakeMaster Zero Line card has National Hydrography Dataset Zero Lines on it. This means these Zero Lines are not always 100% representative for the area you want to survey. But they are usually a good representation for the lake shore and can be used to make an accurate map. Below is an example of what the same data from the previous “no Zero Line” example would look like when used with the LakeMaster Zero Line.
- As you can see the above image has a much smoother and more accurate representation of the Zero Line than not using one. Below is an example of the contours generated from the LakeMaster Zero Line.
- You do notice in a few spots that the LakeMaster Zero Line wasn’t able to control all the contours. This is because the survey was very close to the Zero Line and not enough room was left for the contours to draw. It could also be the result of the shoreline not being accurate. This is a situation when you can use a custom Zero Line to try to get the best results from your survey.
3. Custom Zero Line
- Below is an example of what a custom Zero Line can do. You get a more accurate representation of the shoreline. It also prevents the contours from blowing out onto land due to the survey and Zero Line having a better alignment.
- Below you will see contours from the custom Zero Line. As you can see these contours fit perfectly inside the Zero Line giving you the best representation of the lake.
4. Creating custom Zero Lines
- To create a custom Zero Line you need to use the draw line tool. This can be found under the tools section in the help menu of AutoChart and looks like the image below. Use the “Find” search box at the top of the help menu and type in “Draw Line”.
- Once you have the draw line tool selected all you need to do is trace the shoreline around your lake from the Aerial Imagery Basemap. Once you have finished the shoreline you right click and select the save option that works best for you. The purple line in the following image is an example of where you would place a custom Zero Line for this lake.