diff --git a/modules/hydrodyn/src/Morison.f90 b/modules/hydrodyn/src/Morison.f90
index 36419d3ee3..6329a4117c 100644
--- a/modules/hydrodyn/src/Morison.f90
+++ b/modules/hydrodyn/src/Morison.f90
@@ -2110,6 +2110,8 @@ SUBROUTINE Morison_Init( InitInp, u, p, x, xd, z, OtherState, y, m, Interval, In
             END IF
          
          END DO   !J = 1, InitInp%InpJoints(I)%NConnections
+
+         Vn = Vn*TwoPi/3.0_ReKi ! Semisphere volume is Vn = 2/3 pi \sum (r_MG^3 k)
          
          p%An_End(:,i) = An_drag 
          Amag_drag = Dot_Product(An_drag ,An_drag)
@@ -2127,7 +2129,7 @@ SUBROUTINE Morison_Init( InitInp, u, p, x, xd, z, OtherState, y, m, Interval, In
          ! Constant part of the external hydrodynamic added mass term
          if ( Vmag > 0.0 ) then
             v2D(:,1) = Vn        
-            p%AM_End(:,:,i) = (InitInp%Nodes(I)%JAxCa*InitInp%WtrDens/ Vmag)*matmul(transpose(v2D), v2D) 
+            p%AM_End(:,:,i) = (InitInp%Nodes(I)%JAxCa*InitInp%WtrDens/ Vmag)*matmul(v2D, transpose(v2D))
          end if
          
          ! Constant part of the external hydrodynamic dynamic pressure force
diff --git a/reg_tests/r-test b/reg_tests/r-test
index e8a144a39d..62ce348c8c 160000
--- a/reg_tests/r-test
+++ b/reg_tests/r-test
@@ -1 +1 @@
-Subproject commit e8a144a39d2301bd329e10ce927b5764b174e037
+Subproject commit 62ce348c8cc798e1b7e7c6d826fc2a054512b6d6