Incorrect coordinate space used for meshing

[Jon Hill]

I've successfully used the plugin to generate a mesh from GHSSH shoreline data (which is very cool), but having looked at the geo file in detail, the coordinate space is incorrect; it's in degrees. It should be in metres (assuming my bathymetry is in metres also) otherwise horizontals distances are small and vertical distance will be large.

I think the right thing to do is convert to UTM (http://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system) which gives results in metres, but not sure what to do when you cross a couple of zones. When you cross several you should use the sphere...