diff --git a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css
index d8a4b834..adb8716f 100644
--- a/src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css
+++ b/src/trx-client/trx-frontend/trx-frontend-http/assets/web/style.css
@@ -2085,9 +2085,15 @@ small { color: var(--text-muted); }
   display: grid;
   grid-template-columns: minmax(8.5rem, 11rem) minmax(0, 1fr);
   gap: 1rem;
-  align-items: start;
+  /* The panel takes the full height of the tab, which is what the decode
+     lists inside it size against: FT8, FT4, FT2 and WSPR fill their panel
+     with flex, so a panel sized to its own content collapsed them to their
+     120px minimum however much room was going spare. */
+  align-items: stretch;
 }
 #tab-digital-modes > .sub-tab-bar {
+  /* The list keeps its own height while the panel stretches. */
+  align-self: start;
   flex-direction: column;
   align-items: stretch;
   gap: 0.12rem;
@@ -2130,6 +2136,7 @@ small { color: var(--text-muted); }
   grid-column: 2;
   grid-row: 1;
   min-width: 0;
+  min-height: 0;
 }
 .sub-tab { flex-shrink: 0; background: transparent; border: none; border-bottom: 2px solid transparent; border-radius: 0; padding: 0.35rem 0.75rem; color: var(--text-muted); cursor: pointer; font-size: 0.85rem; height: auto; }
 .sub-tab.active { border-bottom-color: var(--accent-green); color: var(--accent-green); font-weight: 600; }
@@ -2816,23 +2823,26 @@ body.map-fake-fullscreen-active {
 #aprs-packets,
 #ais-messages,
 #vdes-messages { max-height: 360px; overflow-y: auto; border: 1px solid var(--border-light); border-radius: 6px; background: var(--input-bg); font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; }
-#aprs-packets {
-  flex: 0 1 auto;
-  height: calc(100vh - 28rem);
-  min-height: 16rem;
-  max-height: calc(100vh - 28rem);
+/* Fill the panel, the way the FT8, FT4, FT2 and WSPR lists do.  These were
+   sized by formula against the viewport — 100vh minus a guess at everything
+   above them — which stopped matching the moment the panel changed shape, and
+   left a few hundred pixels of the page empty under a scrolling list. */
+#aprs-packets,
+#ais-messages,
+#vdes-messages,
+#hf-aprs-packets {
+  flex: 1 1 0;
+  min-height: 12rem;
+  max-height: none;
 }
-#ais-messages {
-  flex: 0 1 auto;
-  height: calc(100vh - 24rem);
-  min-height: 16rem;
-  max-height: calc(100vh - 24rem);
-}
-#vdes-messages {
-  flex: 0 1 auto;
-  height: calc(100vh - 24rem);
-  min-height: 16rem;
-  max-height: calc(100vh - 24rem);
+/* HF APRS had no container styling at all: no scroller, no frame, no height —
+   its packets simply ran down the page. */
+#hf-aprs-packets {
+  overflow-y: auto;
+  border: 1px solid var(--border-light);
+  border-radius: 6px;
+  background: var(--input-bg);
+  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
 }
 .aprs-packet { font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; font-size: 0.82rem; padding: 0.45rem 0.55rem; border-bottom: 1px solid var(--border); line-height: 1.35; }
 .aprs-packet:last-child { border-bottom: none; }
@@ -3387,7 +3397,7 @@ body.map-fake-fullscreen-active {
 .cw-tone-picker-head { display: flex; align-items: baseline; justify-content: space-between; gap: 0.6rem; margin-bottom: 0.35rem; color: var(--text-muted); font-size: 0.78rem; }
 #cw-tone-waterfall { width: 100%; height: 56px; display: block; border-radius: 6px; background: linear-gradient(180deg, rgba(8, 14, 18, 0.92), rgba(18, 28, 36, 0.98)); cursor: crosshair; }
 .cw-tone-picker.is-auto #cw-tone-waterfall { cursor: not-allowed; }
-#cw-output { max-height: 360px; overflow-y: auto; border: 1px solid var(--border-light); border-radius: 6px; background: var(--input-bg); font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; font-size: 0.85rem; padding: 0.4rem 0.5rem; min-height: 60px; white-space: pre-wrap; word-break: break-all; }
+#cw-output { flex: 1 1 0; max-height: none; overflow-y: auto; border: 1px solid var(--border-light); border-radius: 6px; background: var(--input-bg); font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; font-size: 0.85rem; padding: 0.4rem 0.5rem; min-height: 60px; white-space: pre-wrap; word-break: break-all; }
 .cw-line { line-height: 1.5; }
 .cw-signal-on { width: 10px; height: 10px; border-radius: 50%; background: var(--accent-green); box-shadow: 0 0 6px var(--accent-green); flex-shrink: 0; }
 .cw-signal-off { width: 10px; height: 10px; border-radius: 50%; background: var(--border-light); flex-shrink: 0; }
@@ -4006,14 +4016,10 @@ body[data-operator-layout="broadcast"] #cw-bar-overlay {
   #subtab-aprs {
     min-height: calc(100vh - 14rem);
   }
-  #aprs-packets {
-    min-height: calc(100vh - 26rem);
-  }
-  #ais-messages {
-    min-height: calc(100vh - 22rem);
-  }
+  #aprs-packets,
+  #ais-messages,
   #vdes-messages {
-    min-height: calc(100vh - 22rem);
+    min-height: 60vh;
   }
   .aprs-details-grid {
     grid-template-columns: minmax(0, 1fr);
diff --git a/src/trx-client/trx-frontend/trx-frontend-http/frontend/tests/browser-smoke.mjs b/src/trx-client/trx-frontend/trx-frontend-http/frontend/tests/browser-smoke.mjs
index cabaa179..6b6fcff7 100644
--- a/src/trx-client/trx-frontend/trx-frontend-http/frontend/tests/browser-smoke.mjs
+++ b/src/trx-client/trx-frontend/trx-frontend-http/frontend/tests/browser-smoke.mjs
@@ -47,6 +47,29 @@ try {
   assert.ok(digital.panelBesideSidebar, "the decoder panel does not sit beside the sidebar");
   assert.deepEqual(digital.panelsShown, ["subtab-ft8"], `panels shown: ${JSON.stringify(digital.panelsShown)}`);
   assert.ok(digital.decoders >= 10, `only ${digital.decoders} decoders in the sidebar`);
+
+  // Each decoder's list fills its panel. FT8, FT4, FT2 and WSPR size against
+  // the panel with flex, so a panel sized to its own content collapsed them to
+  // their 120px minimum with the rest of the page left empty; the marine lists
+  // were sized by a viewport formula that stopped matching when the panel
+  // changed shape.
+  for (const [subtab, list] of [["ft8", "ft8-messages"], ["wspr", "wspr-messages"],
+    ["ais", "ais-messages"], ["aprs", "aprs-packets"], ["hf-aprs", "hf-aprs-packets"]]) {
+    await page.locator(`.sub-tab[data-subtab="${subtab}"]`).click();
+    await page.waitForTimeout(150);
+    const filled = await page.evaluate((id) => {
+      const element = document.getElementById(id);
+      const panel = element.closest(".sub-tab-panel");
+      return {
+        list: Math.round(element.getBoundingClientRect().height),
+        panel: Math.round(panel.getBoundingClientRect().height),
+        scrolls: getComputedStyle(element).overflowY,
+      };
+    }, list);
+    assert.ok(filled.list > filled.panel * 0.6,
+      `${subtab}: the list is ${filled.list}px in a ${filled.panel}px panel`);
+    assert.equal(filled.scrolls, "auto", `${subtab}: the list does not scroll on its own`);
+  }
   await page.locator('.tab[data-tab="main"]').click();
   await page.waitForTimeout(200);