Measuring along Longitude axis?

Is there a way in CE to measure along the longitude axis? I want to be able to measure along the longitude axis for route planning on the west coast. I have searched but haven’t found anything. I do have the latitude scale turned on.

I would like to plot a route that is 15-20 miles offshore on the outside of Washington or Oregon. Another thought is staying within 12 miles offshore to keep Starlink running on a normal roaming plan.

Thanks Tim