<para>
  Newer (post 2006 or so) Lowrance devices added a version three of their
  .usr file format that adds depth.   Specify "3" here to use that format
  on write.  
</para>

<para>
<userinput>
 gpsbabel ... -o lowranceusr,wversion=2 -F blah.usr
</userinput>
is exactly the same as
<userinput>
 gpsbabel ... -o lowranceusr -F blah.usr
</userinput>
</para>


<para>
To create a file that contains depth but therefore isn't usable
on older Lowrance products, use this:
<userinput>
 gpsbabel ... -o lowranceusr,wversion=3 -F blah.usr
</userinput>

</para>
