diff --git a/client/src/chunks/ChunkMeshManager.ts b/client/src/chunks/ChunkMeshManager.ts
index f125c708..c26035b7 100644
--- a/client/src/chunks/ChunkMeshManager.ts
+++ b/client/src/chunks/ChunkMeshManager.ts
@@ -36,70 +36,68 @@ export default class ChunkMeshManager {
   private _createOrUpdateMesh(id: BatchId, data: BlocksBufferGeometryData, cache: Map<BatchId, Mesh>, material: Material): Mesh {
     const { positions, normals, uvs, indices, colors, lightLevels, foamLevels, foamLevelsDiag } = data;
 
-    const geometry = new BufferGeometry();
-
-    geometry.setAttribute(
-      'position',
-      new BufferAttribute(positions, CHUNK_BUFFER_GEOMETRY_NUM_POSITION_COMPONENTS),
-    );
-
-    geometry.setAttribute(
-      'normal',
-      new BufferAttribute(normals, CHUNK_BUFFER_GEOMETRY_NUM_NORMAL_COMPONENTS),
-    );
-
-    geometry.setAttribute(
-      'uv',
-      new BufferAttribute(uvs, CHUNK_BUFFER_GEOMETRY_NUM_UV_COMPONENTS),
-    );
+    let mesh = cache.get(id);
 
-    geometry.setAttribute(
-      'color',
-      new BufferAttribute(colors, CHUNK_BUFFER_GEOMETRY_NUM_COLOR_COMPONENTS),
-    );
+    if (mesh) {
+      // Reuse existing geometry — swap typed arrays and mark dirty.
+      // Three.js reuses the WebGL buffer via bufferSubData when byte-size is
+      // unchanged, and only recreates when the size differs. Either path avoids
+      // the dispose() + new BufferGeometry() + new BufferAttribute() overhead.
+      const geometry = mesh.geometry;
+
+      this._swapAttribute(geometry, 'position', positions, CHUNK_BUFFER_GEOMETRY_NUM_POSITION_COMPONENTS);
+      this._swapAttribute(geometry, 'normal', normals, CHUNK_BUFFER_GEOMETRY_NUM_NORMAL_COMPONENTS);
+      this._swapAttribute(geometry, 'uv', uvs, CHUNK_BUFFER_GEOMETRY_NUM_UV_COMPONENTS);
+      this._swapAttribute(geometry, 'color', colors, CHUNK_BUFFER_GEOMETRY_NUM_COLOR_COMPONENTS);
+
+      this._swapOptionalAttribute(geometry, 'lightLevel', lightLevels, CHUNK_BUFFER_GEOMETRY_NUM_LIGHT_LEVEL_COMPONENTS);
+      this._swapOptionalAttribute(geometry, 'foamLevel', foamLevels, CHUNK_BUFFER_GEOMETRY_NUM_FOAM_LEVEL_COMPONENTS);
+      this._swapOptionalAttribute(geometry, 'foamLevelDiag', foamLevelsDiag, CHUNK_BUFFER_GEOMETRY_NUM_FOAM_LEVEL_COMPONENTS);
+
+      // Index may switch between Uint16 and Uint32 depending on vertex count
+      const indexAttr = geometry.getIndex();
+      if (indexAttr && indexAttr.array.constructor === indices.constructor && indexAttr.array.byteLength === indices.byteLength) {
+        indexAttr.array = indices;
+        indexAttr.needsUpdate = true;
+      } else {
+        geometry.setIndex(new BufferAttribute(indices, 1));
+      }
 
-    if (lightLevels) {
-      geometry.setAttribute(
-        'lightLevel',
-        new BufferAttribute(lightLevels, CHUNK_BUFFER_GEOMETRY_NUM_LIGHT_LEVEL_COMPONENTS),
-      );
-    }
+      // Invalidate cached bounds so they are recomputed from the new data
+      geometry.boundingSphere = null;
+      geometry.boundingBox = null;
+      geometry.computeBoundingSphere();
 
-    if (foamLevels) {
-      geometry.setAttribute(
-        'foamLevel',
-        new BufferAttribute(foamLevels, CHUNK_BUFFER_GEOMETRY_NUM_FOAM_LEVEL_COMPONENTS),
-      );
-    }
+      mesh.material = material;
+    } else {
+      const geometry = new BufferGeometry();
 
-    if (foamLevelsDiag) {
-      geometry.setAttribute(
-        'foamLevelDiag',
-        new BufferAttribute(foamLevelsDiag, CHUNK_BUFFER_GEOMETRY_NUM_FOAM_LEVEL_COMPONENTS),
-      );
-    }
+      geometry.setAttribute('position', new BufferAttribute(positions, CHUNK_BUFFER_GEOMETRY_NUM_POSITION_COMPONENTS));
+      geometry.setAttribute('normal', new BufferAttribute(normals, CHUNK_BUFFER_GEOMETRY_NUM_NORMAL_COMPONENTS));
+      geometry.setAttribute('uv', new BufferAttribute(uvs, CHUNK_BUFFER_GEOMETRY_NUM_UV_COMPONENTS));
+      geometry.setAttribute('color', new BufferAttribute(colors, CHUNK_BUFFER_GEOMETRY_NUM_COLOR_COMPONENTS));
 
-    geometry.setIndex(new BufferAttribute(indices, 1));
-    geometry.computeBoundingSphere();
+      if (lightLevels) {
+        geometry.setAttribute('lightLevel', new BufferAttribute(lightLevels, CHUNK_BUFFER_GEOMETRY_NUM_LIGHT_LEVEL_COMPONENTS));
+      }
+      if (foamLevels) {
+        geometry.setAttribute('foamLevel', new BufferAttribute(foamLevels, CHUNK_BUFFER_GEOMETRY_NUM_FOAM_LEVEL_COMPONENTS));
+      }
+      if (foamLevelsDiag) {
+        geometry.setAttribute('foamLevelDiag', new BufferAttribute(foamLevelsDiag, CHUNK_BUFFER_GEOMETRY_NUM_FOAM_LEVEL_COMPONENTS));
+      }
 
-    let mesh = cache.get(id);
+      geometry.setIndex(new BufferAttribute(indices, 1));
+      geometry.computeBoundingSphere();
 
-    if (mesh) {
-      mesh.geometry.dispose();
-      mesh.geometry = geometry;
-      mesh.material = material;
-    } else {
       mesh = new Mesh(geometry, material);
       mesh.name = `batch_${id}`;
 
-      // The mesh has a fixed default position/rotation/scale, so we can skip matrix updates
       mesh.matrixAutoUpdate = false;
       mesh.matrixWorldAutoUpdate = false;
 
       cache.set(id, mesh);
       this._batchIds.add(id);
-
-      // Don't add to scene here - view distance will control when meshes enter the scene
     }
 
     updateAABB(mesh);
@@ -107,6 +105,24 @@ export default class ChunkMeshManager {
     return mesh;
   }
 
+  private _swapAttribute(geometry: BufferGeometry, name: string, data: Float32Array, itemSize: number): void {
+    const attr = geometry.getAttribute(name) as BufferAttribute | undefined;
+    if (attr && attr.array.byteLength === data.byteLength) {
+      attr.array = data;
+      attr.needsUpdate = true;
+    } else {
+      geometry.setAttribute(name, new BufferAttribute(data, itemSize));
+    }
+  }
+
+  private _swapOptionalAttribute(geometry: BufferGeometry, name: string, data: Float32Array | undefined, itemSize: number): void {
+    if (data) {
+      this._swapAttribute(geometry, name, data, itemSize);
+    } else if (geometry.hasAttribute(name)) {
+      geometry.deleteAttribute(name);
+    }
+  }
+
   private _removeMesh(id: BatchId, cache: Map<BatchId, Mesh>): void {
     const mesh = cache.get(id);