How to Make a Google Map of Your Voyage

There are several ways to use Google Maps. Your choices are affected by whether you have the lat / long points or need to get them by drawing manually on the Google maps site. If you want to draw the chart manually and host it on their site, you can just go to maps.google.com and draw it, save it, and get a link to either send people or copy it to your site.

If you want to host it on your own site, you need to use the Google Maps API which makes it possible for you to draw the chart using javascript. Using the API you can either:

  • get the lat/long points from your own records, or
  • get the xml from Google Earth to help you create the javascript.

I will go briefly through these methods and explain the differences.

  Manually Draw Map Code Map
1. Use Google's site Must Draw the map x
2. Use own web site: possible possible
  • Need to see map to draw accurate route
 Must Draw the map x
  • Have list of lat/longs
 x Must Code the map
  • hybrid (some drawn, some points)
 Use Google Earth to transform drawn lines to lat / longs Combine lat/ longs from google earth with your own lat / longs to make one chart

Drawing a Map Manually and hosting it on Google

See example of a drawn map

This is of course the easiest method, but most limited. When you draw a map you have three tools - straight lines, polygons and markers. On a voyage you're mostly going to indicate a point, then another one, and google draws a straight line between them. So if I draw a line between one harbor and the next, the line may very well go over land in between those points unless I add a lot more points to show the path I actually took which zigged and zagged around the land masses. Your position log may not represent all these points, so for trips close in to land it may be easier to draw your route manually. The satellite detail is so good in most places that you'll probably find this is fairly easy to do.

Once you've drawn the map you can either create a link to it, or embed a reference to it on your own web site. You also have the choice of making your map Public so that people could find it in searches, or keep it private for only those with whom you share the link.

Drawing the Map with coded lat/long points

See example code for Coded map

What if you're making an ocean passage? In this case you would find it quite difficult to draw an accurate chart of your trip across the ocean. However, sailors, unlike most hikers or car travellers, usually have records of the latitudes and longitudes they have traversed on their trips. In this case, by pulling some numbers out of your log, making a chart of the trip is relatively easy. However what do you do with these numbers? We've seen that maps.google.com lets you draw lines, but doesn't allow the input of latitudes and longitudes. So we have to turn to javascript code. Luckily it's not too difficult to do a simple line chart with a marker or two if you know how to call javascript from a web page.

More info from Google: Read about the Google Maps API and get a key

Drawing a Map Manually, getting the xml to move it to the API

Ahh - but now I have a map I drew on Google of the route I took through the islands, and an ocean passage chart I created from my own lat longs - how of do I combine them into one chart on my own site? Luckily Google Earth supplies us with a way to get those lat longs off the drawn map. Bring up your hand-drawn chart in Google Earth (notice the link on the top of the map on the google page). Zoom into the area of interest and in the "Places" panel on the left highlight a line you want the parameters of, right click, select Copy, and then paste into an empty code file. Repeat until you have all the lines and markers you want to replicate. This data will be xml data and the Coordinates section will have the lat longs you're looking for. Add these to the chart you coded above and you'll have the whole thing in one chart.