With Pentool created line doesnt show

Hey i created a line using the Pen tool by just simply making to points and hitting Enter.

My problem it that the line only shows when I select the Vector Mask thumbnail for it.

So if I keep drawing something else on a new layer its gone.
I want to use the line as a helping line so i can make a metric form.

What do I do wrong?
If I want to have more then one help line is it possible to put them on the same layer so I dont have to deselect them one by one?

Thanks for the help
Harvyman

I suggest you to create paths instead of Vector Masks on various Color Layers.
Set the tool to (Path) and after selecting this in the Paths Panel you can easily add subpaths to it.