diff --git a/scripts/qa-radio-engine-switch.mjs b/scripts/qa-radio-engine-switch.mjs
index 32b8b288a..9e0bbaad9 100644
--- a/scripts/qa-radio-engine-switch.mjs
+++ b/scripts/qa-radio-engine-switch.mjs
@@ -4,6 +4,7 @@ import { stations, installRadioFixture } from './fixtures/w2/radio.mjs';
 import { blockPaidQaMaps } from './qa-map-policy.mjs';
 import { switchGlobe } from './qa-switch-globe.mjs';
 const url = new URL(process.argv[2]);
+const soak = process.argv.includes('--soak');
 if (
   !['localhost', '127.0.0.1'].includes(url.hostname) ||
   ['', '4173', '4185', '4186', '4187', '4188', '4189', '4194'].includes(
@@ -23,6 +24,20 @@ try {
   const errors = [];
   page.on('pageerror', (e) => errors.push(e.message));
   await installRadioFixture(page);
+  if (soak) await page.evaluateOnNewDocument(() => {
+    const fetch = window.fetch.bind(window);
+    window.qaQuakeReads = 0;
+    window.fetch = (input, init) => {
+      const url = new URL(input?.url ?? input, location.href);
+      if (url.hostname !== 'earthquake.usgs.gov') return fetch(input, init);
+      window.qaQuakeReads++;
+      return Promise.resolve(Response.json({
+        type: 'FeatureCollection',
+        features: [{ type: 'Feature', id: 'qa-austin', properties: { mag: 4.1, time: Date.now(), place: 'Austin' },
+          geometry: { type: 'Point', coordinates: [-97.74, 30.27, 8] } }],
+      }));
+    };
+  });
   await page.goto(url.href);
   await page.waitForFunction(
     () =>
@@ -56,8 +71,53 @@ try {
     window.qaSnapshot = window.qaLayer.getAcceptedCatalogSnapshot();
     return window.__qaRadio.reads;
   });
-  for (const kind of ['cesium', 'navara']) {
+  const client = soak ? await page.createCDPSession() : null;
+  if (soak) await page.evaluate(async () => {
+    const { dataManager, engine } = window.__godsEyeView;
+    await dataManager.setEnabled('earthquakes', true, { origin: 'user' });
+    window.qaModels = new Map([...dataManager.layers].map(([id, entry]) => [id, entry.module]));
+    window.qaEngines = new Map([[engine.kind, engine]]);
+  });
+  const swaps = soak ? 50 : 2, measurements = [], memory = [];
+  let contextListeners;
+  for (let i = 1; i <= swaps; i++) {
+    const kind = i % 2 ? 'cesium' : 'navara';
+    const start = await page.evaluate(() => performance.now());
     await switchGlobe(page, kind);
+    const elapsed = await page.evaluate((start) => performance.now() - start, start);
+    measurements.push({ kind, ms: Math.round(elapsed) });
+    if (soak) {
+      assert.ok(await page.evaluate(() => {
+        const { dataManager, engine } = window.__godsEyeView;
+        const previous = window.qaEngines.get(engine.kind);
+        window.qaEngines.set(engine.kind, engine);
+        return (!previous || previous === engine) && window.qaEngines.size === 2 &&
+          [...window.qaModels].every(([id, model]) => dataManager.layers.get(id)?.module === model) &&
+          window.qaModels.size === 33 && window.qaQuakeReads >= 1 &&
+          dataManager.getEnabledLayerIds().has('earthquakes');
+      }));
+      if ([2, 10, 50].includes(i)) {
+        const { result } = await client.send('Runtime.evaluate', {
+          includeCommandLineAPI: true,
+          returnByValue: true,
+          expression: `(() => {
+            const events = getEventListeners(window.__godsEyeView.engine.host.canvas);
+            return [events.webglcontextlost.length, events.webglcontextrestored.length];
+          })()`,
+        });
+        assert.ok(
+          Array.isArray(result.value) && result.value.length === 2 &&
+            result.value.every((count) => Number.isInteger(count) && count > 0),
+          'the active canvas must expose both WebGL event subscriptions',
+        );
+        contextListeners ??= result.value;
+        assert.deepEqual(result.value, contextListeners, 'warm Navara must release old context listeners');
+        await client.send('HeapProfiler.collectGarbage');
+        const heap = await client.send('Runtime.getHeapUsage');
+        const dom = await client.send('Memory.getDOMCounters');
+        memory.push({ swap: i, contextListeners, jsMiB: Math.round(heap.usedSize / 1048576), ...dom });
+      }
+    }
     const state = await page.evaluate(() => ({
       same:
         window.qaLayer ===
@@ -86,6 +146,14 @@ try {
     assert.equal(state.state.selected.id, stations[10].id);
     assert.equal(state.state.volume, 0.36);
   }
+  if (soak) {
+    const warm = {};
+    for (const kind of ['navara', 'cesium']) {
+      const ms = measurements.slice(2).filter(x => x.kind === kind).map(x => x.ms).sort((a, b) => a - b);
+      warm[kind] = { p50: ms[Math.ceil(ms.length * 0.50) - 1], p95: ms[Math.ceil(ms.length * 0.95) - 1] };
+    }
+    console.log('SOAK', JSON.stringify({ swaps, first: measurements.slice(0, 2), warm, memory }));
+  }
   assert.deepEqual(errors, []);
   console.log(
     'PASS one live radio player, one station directory and the same selection',
diff --git a/src/globe/navara/movers/moverMesh.js b/src/globe/navara/movers/moverMesh.js
index 1822cf3a6..b6b0b4f92 100644
--- a/src/globe/navara/movers/moverMesh.js
+++ b/src/globe/navara/movers/moverMesh.js
@@ -217,7 +217,14 @@ function atlasTexture(atlas, encoded, onLoad) {
   const texture = cesiumSampling(new Texture(), encoded);
   const image = new Image();
   image.crossOrigin = 'anonymous';
+  const release = () => {
+    image.onload = null;
+    texture.image = null;
+    texture.removeEventListener('dispose', release);
+  };
+  texture.addEventListener('dispose', release);
   image.onload = () => {
+    image.onload = null;
     texture.image = image;
     texture.needsUpdate = true;
     onLoad();
diff --git a/src/globe/navara/movers/moverMesh.test.mjs b/src/globe/navara/movers/moverMesh.test.mjs
index 510d5d708..d8a5990d8 100644
--- a/src/globe/navara/movers/moverMesh.test.mjs
+++ b/src/globe/navara/movers/moverMesh.test.mjs
@@ -23,6 +23,37 @@ const spriteOptions = normalizeMoverSetOptions({
   },
 });
 
+test('disposing a sprite atlas drops decoded images and detaches pending load callbacks', (t) => {
+  const previous = globalThis.Image;
+  let image;
+  globalThis.Image = class {
+    constructor() { image = this; }
+  };
+  t.after(() => {
+    if (previous) globalThis.Image = previous;
+    else delete globalThis.Image;
+  });
+  const options = normalizeMoverSetOptions({
+    ...spriteOptions, sprite: {
+      sizePx: 24, atlas: { url: '/bracket.svg', cells: { a: [0, 0, 1, 1] } },
+    },
+  });
+  for (const loaded of [false, true]) {
+    let frames = 0;
+    const mover = createMoverMesh(options, createMoverStore(options), {
+      onTextureLoad: () => frames++,
+    });
+    if (loaded) {
+      image.onload();
+      assert.equal(mover.mesh.material.map.image, image);
+    }
+    mover.dispose();
+    assert.equal(image.onload, null);
+    assert.equal(mover.mesh.material.map.image, null);
+    assert.equal(frames, Number(loaded));
+  }
+});
+
 const basicShader = () => ({
   uniforms: UniformsUtils.clone(ShaderLib.basic.uniforms),
   vertexShader: ShaderLib.basic.vertexShader,
diff --git a/src/globe/navara/overlay.js b/src/globe/navara/overlay.js
index 1b3ce9796..919017608 100644
--- a/src/globe/navara/overlay.js
+++ b/src/globe/navara/overlay.js
@@ -43,6 +43,17 @@ class GevOverlayEffectDesc extends EffectDesc {
     );
   }
 
+  onDestroy() {
+    // Navara removes the pass from its composer; our pass owns its GPU target
+    // and context event handlers until it is explicitly disposed.
+    const pass = this.raw?.rawPass;
+    try {
+      super.onDestroy();
+    } finally {
+      pass?.dispose();
+    }
+  }
+
   // Each drawn frame: the scene depth the overlays test against, then each
   // overlay's own per-frame work (pixel footprint, origin, viewport).
   update(time) {