diff --git a/model/src/CMakeLists.txt b/model/src/CMakeLists.txt
index 3541f99f1..5874b3eba 100644
--- a/model/src/CMakeLists.txt
+++ b/model/src/CMakeLists.txt
@@ -40,15 +40,23 @@ message("ESMF_F90COMPILEPATHS:   ${ESMF_F90COMPILEPATHS}")
 #-------------------------
 # Determine switches
 #-------------------------
-list(APPEND switches "CESMCOUPLED" "NCO" "DIST" "MPI" "PR3" "UQ" "FLX0" "SEED" "ST4" "STAB0" "NL1" "BT1" "DB1" "MLIM" "FLD2" "TR0" "BS0" "RWND" "WNX1" "WNT1" "CRX1" "CRT1" "O0" "O1" "O2" "O3" "O4" "O5" "O6" "O7" "O14" "O15" "IS0" "REF0" "NOGRB") 
+list(APPEND switches "CESMCOUPLED" "DIST" "MPI" "FLX0" "SEED" "ST4" "STAB0" "NL1" "BT1" "DB1" "MLIM" "FLD2" "TR0" "BS0" "RWND" "WNX1" "WNT1" "CRX1" "CRT1" "O0" "O1" "O2" "O3" "O4" "O5" "O6" "O7" "O14" "O15" "IS0" "REF0" "NOGRB" "IC4" "NCO")
+
+if (DEFINED USE_PR3)
+  list(APPEND switches PR3 UQ)
+elseif (DEFINED USE_PR1)
+  list(APPEND switches PR1)
+else()
+  message(FATAL_ERROR "either USE_PR3 or USE_PR1 must be defined")
+endif()
 
-# TODO: need to enamble IC4 with the unstructured implemention  
 if (DEFINED USE_UNSTRUCT)
-  list(APPEND switches "IC0" "PDLIB" "METIS")
+  list(APPEND switches "PDLIB" "METIS")
 else()
-  list(APPEND switches "IC4" "OMPG"  "OMPH") 
+  list(APPEND switches "OMPG"  "OMPH")
 endif()
 
+
 #-------------------------
 # Include list of src files to make file more readable
 # defines variables "ftn_src", "nuopc_mesh_cap_src", "pdlib_src", "scrip_src", and "scripnc_src"
@@ -75,12 +83,14 @@ endif()
 # Determine switch specific files
 # Include check_switches as a function for less verbosity in this CMakeLists.txt
 #-------------------------
+message(STATUS "switches are : ${switches}")
 include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/check_switches.cmake)
 check_switches("${switches}" switch_files)
 
-message(STATUS "----status of source files-----")
+message(STATUS "---")
 message(STATUS "list of always source files is : ${ftn_src}")
 message(STATUS "list of switch files is : ${switch_files}")
+message(STATUS "---")
 
 #-------------------------
 # Now check in SourceMods to see if the file should be used instead
diff --git a/model/src/w3src4md.F90 b/model/src/w3src4md.F90
index a8698d1d2..24dc02d91 100644
--- a/model/src/w3src4md.F90
+++ b/model/src/w3src4md.F90
@@ -2225,8 +2225,16 @@ SUBROUTINE W3SDS4 (A, K, CG, USTAR, USDIR, DEPTH, DAIR, SRHS,    &
       END DO
       !
       ! Computes Breaking probability
+      ! NOTE: for PR1 found that BTH occasionally went negative - so implemented the 
+      ! following fix for this
       !
-      PB = (MAX(SQRT(BTH)-EPSR,0.))**2
+      do ik = IK1,NK
+         if (BTH(ik) < 0.) then
+            PB(ik) = 0.
+         else
+            PB(ik) = (MAX(SQRT(BTH(ik))-EPSR,0.))**2
+         end if
+      end do
       !
       ! Multiplies by 28.16 = 22.0 * 1.6² * 1/2 with
       !  22.0 (Banner & al. 2000, figure 6)
diff --git a/model/src/wav_shel_inp.F90 b/model/src/wav_shel_inp.F90
index 1590b3b38..31f669b2e 100644
--- a/model/src/wav_shel_inp.F90
+++ b/model/src/wav_shel_inp.F90
@@ -167,6 +167,7 @@ subroutine read_shel_config(mpi_comm, mds, time0_overwrite, timen_overwrite)
     character(len=80)   :: linein
     character(len=30)   :: ofile ! w3_cou only
     character(len=8)    :: words(7)=''
+    character(len=256)  :: filename
     logical             :: flflg, flhom, tflagi, prtfrm, flgnml, flh(-7:10)
     integer             :: thrlev = 1
     integer             :: time0(2), timen(2), ttime(2)
@@ -258,16 +259,23 @@ subroutine read_shel_config(mpi_comm, mds, time0_overwrite, timen_overwrite)
     ! Read nml file if available
     !--------------------
 
-    inquire(file=trim(fnmpre)//"ww3_shel.nml", exist=flgnml)
+#ifndef W3_CESMCOUPLED
+    filename = trim(fnmpre)//"ww3_shel.nml"
+#else
+    filename = trim(fnmpre)//"wav_in"
+#endif
+
+    inquire(file=trim(filename), exist=flgnml)
 
     if (flgnml) then
-      open(newunit=ndsi, file=trim(fnmpre)//"ww3_shel.nml", status='old', iostat=ierr)
+
+       open(newunit=ndsi, file=trim(filename), status='old', iostat=ierr)
 
       !--------------------
       ! Read namelist
       !--------------------
 
-      call w3nmlshel (mpi_comm, ndsi, trim(fnmpre)//'ww3_shel.nml', nml_domain, nml_input, &
+      call w3nmlshel (mpi_comm, ndsi, trim(filename), nml_domain, nml_input, &
            nml_output_type, nml_output_date, nml_homog_count, nml_homog_input, ierr)
 
       !--------------------