diff --git a/model/src/w3pro2md.F90 b/model/src/w3pro2md.F90
index a23f893ef..ca79193a9 100644
--- a/model/src/w3pro2md.F90
+++ b/model/src/w3pro2md.F90
@@ -855,6 +855,12 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
     WRITE (NDST,9010)
 #endif
     !
+#ifdef W3_GPU
+!$ACC DATA CREATE(VLCFLY, VLCFLX, VDXX, VDYY, VDXY, CXTOT, CYTOT) &
+!$ACC      CREATE(VFDIFX_FAC, VFDIFY_FAC, VFDIFC_FAC, VQ_OLD)     &
+!$ACC      CREATE(HQFAC, HPFAC)
+!$ACC KERNELS      
+#endif
     VLCFLX = 0.
     VLCFLY = 0.
     VFDIFX = 0.
@@ -879,6 +885,8 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
     !
 #ifdef W3_OMPH
     !$OMP PARALLEL DO PRIVATE (ISEA, IXY)
+#elif W3_GPU
+    !$ACC LOOP INDEPENDENT
 #endif
     !
     DO ISEA=1, NSEA
@@ -899,11 +907,17 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
     !
 #ifdef W3_OMPH
     !$OMP END PARALLEL DO
+#elif W3_GPU
+    !$ACC END KERNELS        
 #endif
     !
     IF ( FLCUR ) THEN
 #ifdef W3_T
       WRITE (NDST,9022)
+#endif
+#ifdef W3_GPU
+!$ACC KERNELS      
+!$ACC LOOP INDEPENDENT      
 #endif
       DO ISEA=1, NSEA
         IXY         = MAPSF(ISEA,3)
@@ -914,11 +928,17 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
              VQ(IXY), CXTOT(IXY), CYTOT(IXY)
 #endif
       END DO
+#ifdef W3_GPU
+!$ACC END KERNELS        
+#endif
     END IF
 
     !
 #ifdef W3_OMPH
     !$OMP PARALLEL DO PRIVATE (ISEA, IX, IY, IXY, CP, CQ)
+#elif W3_GPU
+!$ACC KERNELS      
+!$ACC LOOP INDEPENDENT      
 #endif
     !
     DO ISEA=1, NSEA
@@ -933,6 +953,8 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
     !
 #ifdef W3_OMPH
     !$OMP END PARALLEL DO
+#elif W3_GPU
+    !$ACC END KERNELS      
 #endif
     !
     ! 2.b Diffusion coefficients
@@ -942,6 +964,9 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
 #ifdef W3_OMPH
       !$OMP PARALLEL DO PRIVATE (ISEA, IX, IY, IXY, &
       !$OMP&                     DCELL, XWIND, TFAC, DSS, DNN)
+#elif W3_GPU
+      !$ACC KERNELS      
+      !$ACC LOOP INDEPENDENT      
 #endif
       !
       DO ISEA=1, NSEA
@@ -978,6 +1003,8 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
       !
 #ifdef W3_OMPH
       !$OMP END PARALLEL DO
+#elif W3_GPU
+      !$ACC END KERNELS        
 #endif
       !
     END IF
@@ -990,8 +1017,10 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
       !
 #ifdef W3_OMPH
       !$OMP PARALLEL DO PRIVATE (ISEA, IX, IY, IXY )
+#elif W3_GPU
+      !$ACC KERNELS      
+      !$ACC LOOP INDEPENDENT      
 #endif
-      !
       DO ISEA=1, NSEA
         IX     = MAPSF(ISEA,1)
         IY     = MAPSF(ISEA,2)
@@ -1001,6 +1030,8 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
       !
 #ifdef W3_OMPH
       !$OMP END PARALLEL DO
+#elif W3_GPU
+      !$ACC END KERNELS 
 #endif
       !
       IF ( YFIRST ) THEN
@@ -1055,6 +1086,9 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
       !
 #ifdef W3_OMPH
       !$OMP PARALLEL DO PRIVATE (ISEA, IX, IY, IXY )
+#elif W3_GPU
+      !$ACC KERNELS
+      !$ACC LOOP INDEPENDENT        
 #endif
       !
       DO ISEA=1, NSEA
@@ -1088,11 +1122,16 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
                / CG(IK,ISEA) * CLATS(ISEA)
         END DO
       END IF
+#ifdef W3_GPU
+      !$ACC END KERNELS
+#endif
       !
       ! 3.c Diffusion correction
       !
       IF ( DTME .NE. 0. ) THEN
-
+#ifdef W3_GPU
+      !$ACC KERNELS
+#endif
         IF ( GLOBAL ) THEN
           DO IY=1, NY
             VQ(IY+NX*NY) = VQ(IY)
@@ -1129,8 +1168,9 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
 #ifdef W3_OMPH
         !$OMP PARALLEL DO PRIVATE (ISEA, IX, IY, IXY, &
         !$OMP&                     QXX, QYY, QXY, DVQ )
+#elif W3_GPU
+        !$ACC LOOP INDEPENDENT            
 #endif
-        !
         DO IP=1, NACT
           IXY    = MAPAXY(IP)
           ISEA   = MAPFS(IXY)
@@ -1200,6 +1240,8 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
         !
 #ifdef W3_OMPH
         !$OMP END PARALLEL DO
+#elif W3_GPU
+        !$ACC END KERNELS             
 #endif
         !
       END IF
@@ -1215,6 +1257,9 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
     !
 #ifdef W3_OMPH
     !$OMP PARALLEL DO PRIVATE (ISEA, IXY )
+#elif W3_GPU
+    !$ACC KERNELS
+    !$ACC LOOP INDEPENDENT        
 #endif
     !
     DO ISEA=1, NSEA
@@ -1231,6 +1276,9 @@ SUBROUTINE W3XYP2 ( ISP, DTG, MAPSTA, MAPFS, VQ, VGX, VGY )
     !
 #ifdef W3_OMPH
     !$OMP END PARALLEL DO
+#elif W3_GPU
+    !$ACC END KERNELS
+    !$ACC END DATA          
 #endif
     !
     RETURN
diff --git a/model/src/w3uno2md.F90 b/model/src/w3uno2md.F90
index cb8fce7fc..93ff743d8 100644
--- a/model/src/w3uno2md.F90
+++ b/model/src/w3uno2md.F90
@@ -983,6 +983,10 @@ SUBROUTINE W3UNO2s (MX, MY, NX, NY, CFLL, TRANS, Q, BCLOSE,     &
     !
     ! 1.  Initialize aux. array FLA and closure ------------------------- *
     !
+#ifdef W3_GPU
+    !$ACC DATA CREATE(FLA)
+    !$ACC KERNELS
+#endif
     FLA = 0.
     !
     IF ( BCLOSE ) THEN
@@ -1026,6 +1030,8 @@ SUBROUTINE W3UNO2s (MX, MY, NX, NY, CFLL, TRANS, Q, BCLOSE,     &
     !$OMP QBO, IX, IY, IY2, IX2, QN                   &
 #endif
     !$OMP IXYC, IXYD, QB)
+#elif W3_GPU
+      !$ACC LOOP INDEPENDENT
 #endif
     !
     DO IP=1, NB0
@@ -1073,6 +1079,9 @@ SUBROUTINE W3UNO2s (MX, MY, NX, NY, CFLL, TRANS, Q, BCLOSE,     &
     WRITE (NDST,9011) NB1-NB0, 'BOUNDARY ABOVE'
 #endif
     !
+#ifdef W3_GPU
+      !$ACC LOOP INDEPENDENT
+#endif
     DO IP=NB0+1, NB1
       IXY    = MAPBOU(IP)
       CFL    = CFLL(IXY)
@@ -1099,6 +1108,9 @@ SUBROUTINE W3UNO2s (MX, MY, NX, NY, CFLL, TRANS, Q, BCLOSE,     &
     WRITE (NDST,9011) NB2-NB1, 'BOUNDARY BELOW'
 #endif
     !
+#ifdef W3_GPU
+      !$ACC LOOP INDEPENDENT
+#endif
     DO IP=NB1+1, NB2
       IXY    = MAPBOU(IP)
       CFL    = CFLL(IXY+INC)
@@ -1141,6 +1153,8 @@ SUBROUTINE W3UNO2s (MX, MY, NX, NY, CFLL, TRANS, Q, BCLOSE,     &
     !$OMP       PRIVATE(QOLD), &
 #endif
     !$OMP       PRIVATE (IP, IXY, JN, JP)
+#elif W3_GPU
+      !$ACC LOOP INDEPENDENT
 #endif
     !
     DO IP=1, NACT
@@ -1172,6 +1186,9 @@ SUBROUTINE W3UNO2s (MX, MY, NX, NY, CFLL, TRANS, Q, BCLOSE,     &
     !
 #ifdef W3_OMPH
     !$OMP END PARALLEL DO
+#elif W3_GPU
+    !$ACC END KERNELS
+    !$ACC END DATA
 #endif
     !
 #ifdef W3_T0
diff --git a/model/src/w3wavemd.F90 b/model/src/w3wavemd.F90
index 6db2f03af..fe88eb732 100644
--- a/model/src/w3wavemd.F90
+++ b/model/src/w3wavemd.F90
@@ -1853,6 +1853,9 @@ SUBROUTINE W3WAVE ( IMOD, ODAT, TEND, STAMP, NO_OUT &
               !
               !
               ! Initialize FIELD variable
+#ifdef W3_GPU
+!$ACC UPDATE DEVICE(VA)
+#endif
               FIELD = 0.
               !
               DO ISPEC=1, NSPEC
@@ -1919,6 +1922,9 @@ SUBROUTINE W3WAVE ( IMOD, ODAT, TEND, STAMP, NO_OUT &
 
                 END IF
               END DO
+#ifdef W3_GPU
+!$ACC UPDATE SELF(VA)
+#endif
               !
 #ifdef W3_MPI
               IF ( NRQSG1 .GT. 0 ) THEN
diff --git a/regtests/bin/matrix.base b/regtests/bin/matrix.base
index 824b358f1..c0f37e34d 100755
--- a/regtests/bin/matrix.base
+++ b/regtests/bin/matrix.base
@@ -263,6 +263,10 @@
       echo "$rtst -s PR2_UNO -w work_PR2_UNO              $ww3 ww3_tp2.2" >> matrix.body
       echo "$rtst -s PR2_UNO -w work_PR2_UNO              $ww3 ww3_tp2.3" >> matrix.body
       echo "$rtst -s PR2_UNO -w work_PR2_UNO              $ww3 ww3_tp2.4" >> matrix.body
+      echo "$rtst -s PR2_UNO_GPU -w work_PR2_UNO_GPU      $ww3 ww3_tp2.1" >> matrix.body
+      echo "$rtst -s PR2_UNO_GPU -w work_PR2_UNO_GPU      $ww3 ww3_tp2.2" >> matrix.body
+      echo "$rtst -s PR2_UNO_GPU -w work_PR2_UNO_GPU      $ww3 ww3_tp2.3" >> matrix.body
+      echo "$rtst -s PR2_UNO_GPU -w work_PR2_UNO_GPU      $ww3 ww3_tp2.4" >> matrix.body
       echo "$rtst -s PR2_UNO -w work_PR2_UNO_curv -g curv $ww3 ww3_tp2.4" >> matrix.body
       echo "$rtst -s PR2_UNO -w work_PR2_UNO              $ww3 ww3_tp2.5" >> matrix.body
       echo "$rtst -s PR2_UNO -w work_PR2_UNO_a    -g a    $ww3 ww3_tp2.9" >> matrix.body
@@ -312,6 +316,10 @@
       echo "$rtst -s PR2_UNO_MPI  -w work_PR2_UNO_MPI              -f -p $mpi -n $np $ww3 ww3_tp2.2" >> matrix.body
       echo "$rtst -s PR2_UNO_MPI  -w work_PR2_UNO_MPI              -f -p $mpi -n $np $ww3 ww3_tp2.3" >> matrix.body
       echo "$rtst -s PR2_UNO_MPI  -w work_PR2_UNO_MPI              -f -p $mpi -n $np $ww3 ww3_tp2.4" >> matrix.body
+      echo "$rtst -s PR2_UNO_MPI_GPU -w work_PR2_UNO_MPI_GPU       -f -p $mpi -n $np $ww3 ww3_tp2.1" >> matrix.body
+      echo "$rtst -s PR2_UNO_MPI_GPU -w work_PR2_UNO_MPI_GPU       -f -p $mpi -n $np $ww3 ww3_tp2.2" >> matrix.body
+      echo "$rtst -s PR2_UNO_MPI_GPU -w work_PR2_UNO_MPI_GPU       -f -p $mpi -n $np $ww3 ww3_tp2.3" >> matrix.body
+      echo "$rtst -s PR2_UNO_MPI_GPU -w work_PR2_UNO_MPI_GPU       -f -p $mpi -n $np $ww3 ww3_tp2.4" >> matrix.body
       echo "$rtst -s PR2_UNO_MPI  -w work_PR2_UNO_curv_MPI -g curv -f -p $mpi -n $np $ww3 ww3_tp2.4" >> matrix.body
       echo "$rtst -s PR2_UNO_MPI  -w work_PR2_UNO_MPI              -f -p $mpi -n $np $ww3 ww3_tp2.5" >> matrix.body
       echo "$rtst -s PR2_UNO_MPI  -w work_PR2_UNO_a_MPI    -g a    -f -p $mpi -n $np $ww3 ww3_tp2.9" >> matrix.body
diff --git a/regtests/ww3_tp2.1/input/switch_PR2_UNO_GPU b/regtests/ww3_tp2.1/input/switch_PR2_UNO_GPU
new file mode 100644
index 000000000..733d91d56
--- /dev/null
+++ b/regtests/ww3_tp2.1/input/switch_PR2_UNO_GPU
@@ -0,0 +1 @@
+NOGRB SHRD GPU PR2 UNO FLX2 LN0 ST0 NL0 BT0 DB0 TR0 BS0 IC0 IS0 REF0 WNT1 WNX1 CRT1 CRX1 O0 O1 O2 O3 O4 O5 O6 O7 O10 O11
diff --git a/regtests/ww3_tp2.1/input/switch_PR2_UNO_MPI_GPU b/regtests/ww3_tp2.1/input/switch_PR2_UNO_MPI_GPU
new file mode 100644
index 000000000..21c790cc2
--- /dev/null
+++ b/regtests/ww3_tp2.1/input/switch_PR2_UNO_MPI_GPU
@@ -0,0 +1 @@
+NOGRB DIST MPI GPU PR2 UNO FLX2 LN0 ST0 NL0 BT0 DB0 TR0 BS0 IC0 IS0 REF0 WNT1 WNX1 CRT1 CRX1 O0 O1 O2 O3 O4 O5 O6 O7 O10 O11
diff --git a/regtests/ww3_tp2.2/input/switch_PR2_UNO_GPU b/regtests/ww3_tp2.2/input/switch_PR2_UNO_GPU
new file mode 100644
index 000000000..69bb8a2f8
--- /dev/null
+++ b/regtests/ww3_tp2.2/input/switch_PR2_UNO_GPU
@@ -0,0 +1 @@
+NOGRB SHRD PR2 UNO FLX2 LN0 ST0 NL0 BT0 DB0 TR0 BS0 IC0 IS0 REF0 WNT1 WNX1 CRT1 CRX1 O0 O1 O2 O3 O4 O5 O6 O7 O10 O11
diff --git a/regtests/ww3_tp2.2/input/switch_PR2_UNO_MPI_GPU b/regtests/ww3_tp2.2/input/switch_PR2_UNO_MPI_GPU
new file mode 100644
index 000000000..21c790cc2
--- /dev/null
+++ b/regtests/ww3_tp2.2/input/switch_PR2_UNO_MPI_GPU
@@ -0,0 +1 @@
+NOGRB DIST MPI GPU PR2 UNO FLX2 LN0 ST0 NL0 BT0 DB0 TR0 BS0 IC0 IS0 REF0 WNT1 WNX1 CRT1 CRX1 O0 O1 O2 O3 O4 O5 O6 O7 O10 O11
diff --git a/regtests/ww3_tp2.3/input/switch_PR2_UNO_GPU b/regtests/ww3_tp2.3/input/switch_PR2_UNO_GPU
new file mode 100644
index 000000000..733d91d56
--- /dev/null
+++ b/regtests/ww3_tp2.3/input/switch_PR2_UNO_GPU
@@ -0,0 +1 @@
+NOGRB SHRD GPU PR2 UNO FLX2 LN0 ST0 NL0 BT0 DB0 TR0 BS0 IC0 IS0 REF0 WNT1 WNX1 CRT1 CRX1 O0 O1 O2 O3 O4 O5 O6 O7 O10 O11
diff --git a/regtests/ww3_tp2.3/input/switch_PR2_UNO_MPI_GPU b/regtests/ww3_tp2.3/input/switch_PR2_UNO_MPI_GPU
new file mode 100644
index 000000000..21c790cc2
--- /dev/null
+++ b/regtests/ww3_tp2.3/input/switch_PR2_UNO_MPI_GPU
@@ -0,0 +1 @@
+NOGRB DIST MPI GPU PR2 UNO FLX2 LN0 ST0 NL0 BT0 DB0 TR0 BS0 IC0 IS0 REF0 WNT1 WNX1 CRT1 CRX1 O0 O1 O2 O3 O4 O5 O6 O7 O10 O11
diff --git a/regtests/ww3_tp2.4/input/switch_PR2_UNO_GPU b/regtests/ww3_tp2.4/input/switch_PR2_UNO_GPU
new file mode 100644
index 000000000..733d91d56
--- /dev/null
+++ b/regtests/ww3_tp2.4/input/switch_PR2_UNO_GPU
@@ -0,0 +1 @@
+NOGRB SHRD GPU PR2 UNO FLX2 LN0 ST0 NL0 BT0 DB0 TR0 BS0 IC0 IS0 REF0 WNT1 WNX1 CRT1 CRX1 O0 O1 O2 O3 O4 O5 O6 O7 O10 O11
diff --git a/regtests/ww3_tp2.4/input/switch_PR2_UNO_MPI_GPU b/regtests/ww3_tp2.4/input/switch_PR2_UNO_MPI_GPU
new file mode 100644
index 000000000..21c790cc2
--- /dev/null
+++ b/regtests/ww3_tp2.4/input/switch_PR2_UNO_MPI_GPU
@@ -0,0 +1 @@
+NOGRB DIST MPI GPU PR2 UNO FLX2 LN0 ST0 NL0 BT0 DB0 TR0 BS0 IC0 IS0 REF0 WNT1 WNX1 CRT1 CRX1 O0 O1 O2 O3 O4 O5 O6 O7 O10 O11