anchor.diff:              stage_uh_vh_elev(2:3) = 0.0_dp
           else
   
  -            ! Much experimentation was conducted here. This problem is sensitive to
  -            ! imperfections in our semi-transmissive boundary conditions which allow a 
  -            ! stage forcing. (Not too surprising, because the boundary is quite close to the
  -            ! coast, in 'not very deep' water).
   
               select case(boundary_type)
  -
  -            case('boundary_stage_transmissive_normal_momentum')
  -                ! Do nothing, because we do not need uh/vh.
  -                stage_uh_vh_elev(2:3) = 0.0_dp 
  -
  -            case('boundary_stage_transmissive_momentum')
  -                ! Do nothing, because we do not need uh/vh.
  -                stage_uh_vh_elev(2:3) = 0.0_dp 
   
               case('boundary_stage_radiation_momentum') 
                   ! These will never be used for this boundary
  -                stage_uh_vh_elev(2:3) = 0.0_dp
  -
  -            case('flather_with_vh_equal_zero') 
  -                ! This absorbs, but also distorts the stage at the boundary too much when
  -                ! wave frequencies are lower
                   stage_uh_vh_elev(2:3) = 0.0_dp
   
               case('flather_with_vh_from_continuity')
  
positive.code:     call md%set_point_gauges_from_csv("point_gauges.csv", skip_header=1_ip)
     
      do j = 1, size(md%domains) 
          ! Boundary. Care is required in this problem, because the boundary is so close to the
          ! coast -- reflections can be a problem. A number of approaches can be tested by 
          ! changing 'boundary_type' in the local_routines module
          select case(boundary_type)
          case('boundary_stage_transmissive_normal_momentum')
              md%domains(j)%boundary_subroutine => boundary_stage_transmissive_normal_momentum
          case('boundary_stage_transmissive_momentum')
              md%domains(j)%boundary_subroutine => boundary_stage_transmissive_momentum
          case('flather_with_vh_from_continuity')
              md%domains(j)%boundary_subroutine => flather_boundary
          case('flather_with_vh_equal_zero')
              md%domains(j)%boundary_subroutine => flather_boundary
          case('boundary_stage_radiation_momentum')
              md%domains(j)%boundary_subroutine => boundary_stage_radiation_momentum
  
negative.code:     use global_mod, only: ip, dp, minimum_allowed_depth, default_nonlinear_timestepping_method
      use domain_mod, only: domain_type
      use multidomain_mod, only: multidomain_type, setup_multidomain, test_multidomain_mod
      use boundary_mod, only: flather_boundary, boundary_stage_radiation_momentum
      use local_routines
      use timer_mod
      use logging_mod, only: log_output_unit
  