Convert a 2D marine chart into a 3D Sketchup drawing

I am a scuba diver and want to build 3-dimensional models for my favourite underwater sites. Charts are available for these sites that display all the contour lines at half-meter intervals. The challenge is that these are bitmap charts, which first need to be converted to vector graphics and then thicknesses assigned to each layer. And to further complicate it, the lines on the charts have gaps, which need to be identified and fixed before converting. There is a video on Youtube that shows how to do this here: [login to view URL] I have attached a sample screenshot, with the red box showing the area I want to have turned into a 3D model. I will ultimately have about 20 of these to do, so am looking for an estimation of effort and price per model. The first one will undoubtedly take you longer, but once you are familiar with the process the others should go quicker. The output needs to be in a Google Sketchup format, so I can open it and print out the drawing or send it to my 3D printer.