anchor.diff:      use domain_mod, only: domain_type
       use multidomain_mod, only: multidomain_type, setup_multidomain, test_multidomain_mod
       use boundary_mod, only: boundary_stage_transmissive_normal_momentum, flather_boundary, &
  -        boundary_stage_transmissive_momentum
  +        boundary_stage_transmissive_momentum, boundary_stage_radiation_momentum
       use local_routines
       use timer_mod
       use logging_mod, only: log_output_unit
  
positive.code:         md%domains(1)%boundary_subroutine => flather_boundary
      case('flather_with_vh_equal_zero')
          md%domains(1)%boundary_subroutine => flather_boundary
      case default
          stop "Invalid boundary_type value"
      end select
  
negative.code:             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).
  