Sorry if this is a basic question but I am having a pretty tough time trying to figure this out.
 
I am building a route for a race and want to have it start at a starting line.  What I am trying to do seems pretty simple but for the life of me cannot figure it out.
 
Simplest example, three marks, one is the starboard end, and one the port end, and one the first mark.
 
What I assumed would work was create the marks, build a route with the marks and then (via the right mouse pop up) set #1 to the starboard end and #2 to the port and all would be good, but no joy.
 
How do I get marks 1 & 2 to be the starting line and not the first two marks?  Every thing I have tried results in the first leg being #1 to #2 instead of a starting line and then #3. 
 
Or at least that is what I am assuming, I have start line turned on in display setting and when I check the route details it includes the “starting line” in the total distance.
 
Any help would be much appreciated as I am pulling my hair out a bit on this.

Thanks
John