diff --git a/src/underworld3/adaptivity.py b/src/underworld3/adaptivity.py
index 5442960d0..c22a1fb8b 100644
--- a/src/underworld3/adaptivity.py
+++ b/src/underworld3/adaptivity.py
@@ -148,10 +148,9 @@ def create_metric(
     # Create metric MeshVariable
     metric = uw.discretisation.MeshVariable(name, mesh, 1, degree=1)
 
-    with mesh.access(metric):
-        # Convert to metric tensor: M = 1/h² × I (isotropic)
-        # This is dimension-independent: same formula for 2D and 3D
-        metric.data[:, 0] = 1.0 / (h_values ** 2)
+    # Convert to metric tensor: M = 1/h² × I (isotropic)
+    # This is dimension-independent: same formula for 2D and 3D
+    metric.data[:, 0] = 1.0 / (h_values ** 2)
 
     return metric
 
@@ -402,8 +401,7 @@ def metric_from_field(
         )
 
     # Get indicator values
-    with mesh.access(indicator):
-        ind_values = indicator.data[:, 0].copy()
+    ind_values = indicator.data[:, 0].copy()
 
     # Handle indicator bounds
     if indicator_min is None:
@@ -647,10 +645,9 @@ def mesh2mesh_swarm(mesh0, mesh1, swarm0, swarmVarList, proxy=True, verbose=Fals
     if the returned swarm is ephemeral
     """
 
-    with swarm0.access():
-        swarm_data = swarm0._particle_coordinates.data.copy()
-        for swarmVar in swarmVarList:
-            swarm_data = np.hstack((swarm_data, np.ascontiguousarray(swarmVar.data.astype(float))))
+    swarm_data = swarm0._particle_coordinates.data.copy()
+    for swarmVar in swarmVarList:
+        swarm_data = np.hstack((swarm_data, np.ascontiguousarray(swarmVar.data.astype(float))))
 
     s_coords0 = np.ascontiguousarray(swarm_data[:, 0 : mesh0.dim])
 
@@ -891,8 +888,7 @@ def mesh2mesh_meshVariable(meshVar0, meshVar1, verbose=False):
 
     # print(f"Map data to swarm (rbf) - points = {tmp_swarm.dm.getSize()}", flush=True)
 
-    with tmp_swarm.access(tmp_varS):
-        tmp_varS.data[...] = meshVar0.rbf_interpolate(tmp_swarm._particle_coordinates.data)
+    tmp_varS.data[...] = meshVar0.rbf_interpolate(tmp_swarm._particle_coordinates.data)
 
     # print(f"Distribute swarm", flush=True)
 
diff --git a/src/underworld3/coordinates.py b/src/underworld3/coordinates.py
index 3f50b90b1..a8a0b71a7 100644
--- a/src/underworld3/coordinates.py
+++ b/src/underworld3/coordinates.py
@@ -770,7 +770,8 @@ def from_cartesian(self, x, y, z):
         Examples
         --------
         >>> # Convert mesh points to geographic for comparison with data
-        >>> x, y, z = mesh.data[:, 0], mesh.data[:, 1], mesh.data[:, 2]
+        >>> coords = mesh.X.coords
+        >>> x, y, z = coords[:, 0], coords[:, 1], coords[:, 2]
         >>> lon, lat, depth = mesh.geo.from_cartesian(x, y, z)
         """
         # Nondimensionalise ellipsoid for numeric coordinate conversion
@@ -834,7 +835,7 @@ def points_from_cartesian(self, points_xyz):
         Examples
         --------
         >>> # Export mesh coordinates to geographic
-        >>> mesh_xyz = mesh.data  # or mesh.CoordinateSystem.coords
+        >>> mesh_xyz = mesh.X.coords
         >>> mesh_llz = mesh.geo.points_from_cartesian(mesh_xyz)
         """
         import numpy as np
diff --git a/src/underworld3/discretisation/discretisation_mesh.py b/src/underworld3/discretisation/discretisation_mesh.py
index 85a03d03a..8859464a4 100644
--- a/src/underworld3/discretisation/discretisation_mesh.py
+++ b/src/underworld3/discretisation/discretisation_mesh.py
@@ -2984,9 +2984,8 @@ def update_lvec(self, swarm_sync=True):
             # traverse subdms, taking user generated data in the subdm
             # local vec, pushing it into a global sub vec
             for var, subiset, subdm in zip(self.vars.values(), isets, dms):
-                # Use access pattern to ensure vector is available
-                with self.access(var):
-                    lvec = var.vec
+                # var.vec lazily creates the PETSc local vector on first access
+                lvec = var.vec
                 subvec = a_global.getSubVector(subiset)
                 subdm.localToGlobal(lvec, subvec, addv=False)
                 a_global.restoreSubVector(subiset, subvec)
diff --git a/src/underworld3/function/_function.pyx b/src/underworld3/function/_function.pyx
index d07eb41eb..c1d1bce3e 100644
--- a/src/underworld3/function/_function.pyx
+++ b/src/underworld3/function/_function.pyx
@@ -892,8 +892,7 @@ def _clement_to_work_variable(expr, mesh, derivfns):
         result = np.full(n_nodes, result[0])
 
     # Store in work variable
-    with mesh.access(work_var):
-        work_var.data[:, 0] = result.flatten()
+    work_var.data[:, 0] = result.flatten()
 
     return work_var
 
diff --git a/src/underworld3/function/functions_unit_system.py b/src/underworld3/function/functions_unit_system.py
index b567081da..4d7c0a31a 100644
--- a/src/underworld3/function/functions_unit_system.py
+++ b/src/underworld3/function/functions_unit_system.py
@@ -147,7 +147,7 @@ def _evaluate_impl(
     --------
     >>> # Works with both dimensional and non-dimensional coords
     >>> result = uw.function.evaluate(T.sym, T.coords)  # dimensional coords
-    >>> result = uw.function.evaluate(T.sym, mesh.data[:, :2])  # non-dimensional
+    >>> result = uw.function.evaluate(T.sym, mesh.X.coords[:, :2])  # non-dimensional
     >>> if hasattr(result, 'to'):
     ...     result_K = result.to('K')  # Unit conversion
     """
diff --git a/src/underworld3/meshing/surfaces.py b/src/underworld3/meshing/surfaces.py
index 21191979b..ed3511f80 100644
--- a/src/underworld3/meshing/surfaces.py
+++ b/src/underworld3/meshing/surfaces.py
@@ -2122,7 +2122,8 @@ def transfer_normals(
 
         Args:
             mesh: The mesh to transfer normals to
-            coords: Optional coordinates to query. If None, uses mesh.data
+            coords: Optional coordinates to query. If None, uses the mesh's
+                own vertex coordinates (model space)
             normal_var: Optional existing MeshVariable
             variable_name: Name for new variable
 
diff --git a/src/underworld3/swarm.py b/src/underworld3/swarm.py
index c648f01de..f60921bb6 100644
--- a/src/underworld3/swarm.py
+++ b/src/underworld3/swarm.py
@@ -317,7 +317,6 @@ def __init__(
         # add to swarms dict
 
         self.swarm._vars[self.clean_name] = self
-        self._is_accessed = False
 
         # Initialize proxy flags first before creating proxy variable
         self._updating_proxy = False  # Flag to prevent recursive proxy updates
@@ -1230,19 +1229,18 @@ def _rbf_reduce_to_meshVar(self, meshVar, verbose=False):
         # Use cached KDTree for interpolation (avoids redundant index construction)
         kd = meshVar._get_kdtree()
 
-        with self.swarm.access():
-            d, n = kd.query(self.swarm.data, k=1, sqr_dists=False)  # need actual distances
+        d, n = kd.query(self.swarm.data, k=1, sqr_dists=False)  # need actual distances
 
-            node_values = np.zeros((meshVar.coords.shape[0], self.num_components))
-            w = np.zeros(meshVar.coords.shape[0])
+        node_values = np.zeros((meshVar.coords.shape[0], self.num_components))
+        w = np.zeros(meshVar.coords.shape[0])
 
-            if not self._nn_proxy:
-                for i in range(self.local_size):
-                    # if b[i]:
-                    node_values[n[i], :] += self.data[i, :] / (1.0e-24 + d[i])
-                    w[n[i]] += 1.0 / (1.0e-24 + d[i])
+        if not self._nn_proxy:
+            for i in range(self.local_size):
+                # if b[i]:
+                node_values[n[i], :] += self.data[i, :] / (1.0e-24 + d[i])
+                w[n[i]] += 1.0 / (1.0e-24 + d[i])
 
-                node_values[np.where(w > 0.0)[0], :] /= w[np.where(w > 0.0)[0]].reshape(-1, 1)
+            node_values[np.where(w > 0.0)[0], :] /= w[np.where(w > 0.0)[0]].reshape(-1, 1)
 
         # 2 - set NN vals on mesh var where w == 0.0
 
@@ -4594,147 +4592,6 @@ def apply_snapshot_payload(self, payload: dict) -> None:
             # that garbage (exposed by the SWARM-01 invalidation fix).
             var.data[...] = saved
 
-    def _legacy_access(self, *writeable_vars: SwarmVariable):
-        """
-        This context manager makes the underlying swarm variables data available to
-        the user. The data should be accessed via the variables `data` handle.
-
-        As default, all data is read-only. To enable writeable data, the user should
-        specify which variable they wish to modify.
-
-        At the conclusion of the users context managed block, numerous further operations
-        will be automatically executed. This includes swarm parallel migration routines
-        where the swarm's `particle_coordinates` variable has been modified. The swarm
-        variable proxy mesh variables will also be updated for modifed swarm variables.
-
-        Parameters
-        ----------
-        writeable_vars
-            The variables for which data write access is required.
-
-        Example
-        -------
-
-        >>> import underworld3 as uw
-        >>> someMesh = uw.discretisation.FeMesh_Cartesian()
-        >>> with someMesh._deform_mesh():
-        ...     someMesh.data[0] = [0.1,0.1]
-        >>> someMesh.data[0]
-        array([ 0.1,  0.1])
-        """
-        import time
-
-        uw.timing._incrementDepth()
-        stime = time.time()
-
-        deaccess_list = []
-        for var in self._vars.values():
-            # if already accessed within higher level context manager, continue.
-            if var._is_accessed == True:
-                continue
-            # set flag so variable status can be known elsewhere
-            var._is_accessed = True
-            # add to de-access list to rewind this later
-            deaccess_list.append(var)
-            # grab numpy object, setting read only if necessary
-            var._data = self.dm.getField(var.clean_name).reshape((-1, var.num_components))
-            assert var._data is not None
-            if var not in writeable_vars:
-                var._old_data_flag = var._data.flags.writeable
-                var._data.flags.writeable = False
-            else:
-                # increment variable state
-                var._increment()
-
-            # make *view* for each var component
-            if var._proxy:
-                for i in range(0, var.shape[0]):
-                    for j in range(0, var.shape[1]):
-                        var._data_container[i, j] = var._data_container[i, j]._replace(
-                            data=var._data[:, var._data_layout(i, j)],
-                        )
-
-        # if particles moving, update swarm state
-        if self._particle_coordinates in writeable_vars:
-            self._increment()
-
-        # Create a class which specifies the required context
-        # manager hooks (`__enter__`, `__exit__`).
-        class exit_manager:
-            def __init__(self, swarm):
-                self.em_swarm = swarm
-
-            def __enter__(self):
-
-                pass
-
-            def __exit__(self, *args):
-
-                for var in self.em_swarm.vars.values():
-                    # only de-access variables we have set access for.
-                    if var not in deaccess_list:
-                        continue
-                    # set this back, although possibly not required.
-                    if var not in writeable_vars:
-                        var._data.flags.writeable = var._old_data_flag
-                    var._data = None
-                    self.em_swarm.dm.restoreField(var.clean_name)
-                    var._is_accessed = False
-                # do particle migration if coords changes
-
-                if self.em_swarm._particle_coordinates in writeable_vars:
-                    # let's use the mesh index to update the particles owning cells.
-                    # note that the `petsc4py` interface is more convenient here as the
-                    # `SwarmVariable.data` interface is controlled by the context manager
-                    # that we are currently within, and it is therefore too easy to
-                    # get things wrong that way.
-                    #
-                    #
-
-                    # if uw.mpi.size > 1:
-                    #     coords = self.em_swarm.dm.getField("DMSwarmPIC_coor").reshape(
-                    #         (-1, self.em_swarm.dim)
-                    #     )
-
-                    #     self.em_swarm.dm.restoreField("DMSwarmPIC_coor")
-
-                    #     ## We'll need to identify the new processes here and update the particle rank value accordingly
-                    #
-
-                    # Even if only on one process, migrate needs to be called to remove particles that are
-                    # not in the domain.
-
-                    self.em_swarm.migrate(
-                        remove_sent_points=True,
-                        delete_lost_points=self.em_swarm._clip_to_mesh,
-                    )
-
-                    # void these things too
-                    self.em_swarm._index = None
-                    self.em_swarm._nnmapdict = {}
-
-                # do var updates
-                for var in self.em_swarm.vars.values():
-                    # if swarm migrated, update all.
-                    # if var updated, update var.
-                    if (self.em_swarm._particle_coordinates in writeable_vars) or (
-                        var in writeable_vars
-                    ):
-                        var._update()
-
-                    if var._proxy:
-                        for i in range(0, var.shape[0]):
-                            for j in range(0, var.shape[1]):
-                                # var._data_ij[i, j] = None
-                                var._data_container[i, j] = var._data_container[i, j]._replace(
-                                    data=f"SwarmVariable[...].data is only available within mesh.access() context",
-                                )
-
-                uw.timing._decrementDepth()
-                uw.timing.log_result(time.time() - stime, "Swarm.access", 1)
-
-        return exit_manager(self)
-
     def access(self, *writeable_vars: SwarmVariable):
         """
         Dummy access manager that provides deferred sync for backward compatibility.
@@ -5176,9 +5033,8 @@ def __init__(
 
         nswarm.dm.migrate(remove_sent_points=True)
 
-        with nswarm.access(nX0, nI0):
-            nX0.data[:, :] = coords
-            nI0.data[:, 0] = range(0, coords.shape[0])
+        nX0.data[:, :] = coords
+        nI0.data[:, 0] = range(0, coords.shape[0])
 
         self._nswarm = nswarm
         self._nX0 = nX0
@@ -5199,11 +5055,9 @@ def advection(
         step_limit=True,
     ):
 
-        with self.access(self._X0):
-            self._X0.data[...] = self._nX0.data[...]
+        self._X0.data[...] = self._nX0.data[...]
 
-        with self.access(self._nR0):
-            self._nR0.data[...] = uw.mpi.rank
+        self._nR0.data[...] = uw.mpi.rank
 
         super().advection(
             V_fn,
diff --git a/src/underworld3/utilities/nd_array_callback.py b/src/underworld3/utilities/nd_array_callback.py
index 5ce1b0867..d0bafe87e 100644
--- a/src/underworld3/utilities/nd_array_callback.py
+++ b/src/underworld3/utilities/nd_array_callback.py
@@ -421,9 +421,9 @@ def delay_callbacks_global(context_info=None):
 
         Example
         -------
-        >>> with NDArray_With_Callback.delay_callbacks_global("mesh update"):
-        ...     mesh.data[0] = new_pos
-        ...     swarm.data += displacement
+        >>> with NDArray_With_Callback.delay_callbacks_global("field update"):
+        ...     temperature.array[...] = new_T
+        ...     material.array[...] = new_material
         # All callbacks from all arrays fire here
         """