When things are working properly the relief looks blotchy with the mesh still in place.
I was happy so I deleted the mesh.
I then used the second zero height relief to effectively clip the back of the fishing boat cab by merging lowest. The cab looked a little narrow so I stretched it towards the back of the boat and then nudged it forward until I was happy.
I then used the slice command to take off the zero height relief.
After the slice tool is used the top relief shows up. This is on a different plane than the lower slice. The original relief is still in place and needs to be moved to the side.
Before routing I need to duplicate the two layers of hull and then flip them to form the other side of the boat.