diff --git a/bandopen_sources.go b/bandopen_sources.go
index 424c439..8dbdd3f 100644
--- a/bandopen_sources.go
+++ b/bandopen_sources.go
@@ -126,7 +126,13 @@ func (a *App) startBandOpenFeed() {
 		a.pskr = nil
 	}
 	s := a.GetBandOpenSettings()
+	a.bandOpen.on.Store(s.Enabled)
 	if !s.Enabled {
+		// Put out whatever is currently lit. Leaving the badges up would keep
+		// announcing an opening from a watch that is now off, and they only fade
+		// on a timer fed by spots this path no longer looks at — so they would
+		// hang there until the app restarted.
+		a.clearBandOpenings()
 		return
 	}
 	// Every spot is measured from the operator's position. Without one there is
diff --git a/bandopening.go b/bandopening.go
index 57f3876..d75c71a 100644
--- a/bandopening.go
+++ b/bandopening.go
@@ -11,6 +11,7 @@ import (
 	"fmt"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"hamlog/internal/applog"
@@ -21,6 +22,13 @@ import (
 )
 
 type bandOpenState struct {
+	// on mirrors the "Watch for band openings" setting.
+	//
+	// Cached rather than read per spot: this is the cluster hot path, where a
+	// settings query per spot is exactly what the rest of this file avoids.
+	// startBandOpenFeed owns it — it runs at startup and again on every save, so
+	// the switch takes effect without a restart.
+	on   atomic.Bool
 	mu   sync.Mutex
 	det  *bandopen.Detector
 	last []bandopen.Opening // most recent first, for the UI
@@ -45,6 +53,16 @@ const maxRememberedOpenings = 20
 
 // detectBandOpening feeds one spot to the detector and announces a hit.
 func (a *App) detectBandOpening(s cluster.Spot) {
+	// The watch has to be switched on.
+	//
+	// It was not checked here at all: the setting only ever governed the extra
+	// DATA SOURCES (the RBN nodes and the PSK Reporter feed), while the detector
+	// itself ran on every ordinary cluster spot. So an operator who had never
+	// enabled the watch still got opening banners, from a feature they had
+	// deliberately left off.
+	if !a.bandOpen.on.Load() {
+		return
+	}
 	// No operator grid = no distance and no bearing on the spot, and the whole
 	// detection rests on those two. Say nothing rather than guess.
 	if !a.opSet || s.DistanceKm <= 0 || !bandopen.Watched(s.Band) {
@@ -122,6 +140,21 @@ func (a *App) GetLiveOpenings() []bandopen.Opening {
 	return out
 }
 
+// clearBandOpenings puts out every lit badge and forgets the detector's window.
+// Called when the watch is switched off: the badges fade on a timer fed by
+// spots the detector no longer looks at, so without this they would stay up
+// until the next restart. The remembered list is left alone — those openings
+// really did happen, and the operator may still want to see what he missed.
+func (a *App) clearBandOpenings() {
+	a.bandOpen.mu.Lock()
+	defer a.bandOpen.mu.Unlock()
+	a.bandOpen.live = nil
+	a.bandOpen.aliveUntil = nil
+	// Drop the accumulated spot window too, so switching the watch back on starts
+	// from what is on the air now rather than from an hour-old burst.
+	a.bandOpen.det = nil
+}
+
 // announceOpening logs and pushes one detection. Shared by both feeds — the
 // cluster path here and the PSK Reporter path in bandopen_sources.go — so an
 // opening reads the same however it was noticed.
diff --git a/bandopening_gate_test.go b/bandopening_gate_test.go
new file mode 100644
index 0000000..7acb4d7
--- /dev/null
+++ b/bandopening_gate_test.go
@@ -0,0 +1,65 @@
+package main
+
+import (
+	"testing"
+	"time"
+
+	"hamlog/internal/bandopen"
+	"hamlog/internal/cluster"
+)
+
+// The "Watch for band openings" switch has to gate the DETECTOR, not just the
+// extra data sources.
+//
+// It originally governed only the RBN nodes and the PSK Reporter feed, while
+// the detector itself ran on every ordinary cluster spot — so an operator who
+// had never enabled the watch still got opening banners for a feature he had
+// deliberately left off. That is what this pins.
+func TestBandOpenWatchGatesTheDetector(t *testing.T) {
+	spot := func() cluster.Spot {
+		return cluster.Spot{
+			DXCall: "EA1ABC", Band: "6m", DistanceKm: 1400, ShortPath: 210,
+			ReceivedAt: time.Now(),
+		}
+	}
+
+	// Switched off: the spot must not even reach the detector.
+	off := &App{opSet: true, opLat: 48.0, opLon: 2.0}
+	off.detectBandOpening(spot())
+	if off.bandOpen.det != nil {
+		t.Error("the detector ran with the watch switched off")
+	}
+
+	// Switched on: the same spot is accepted (one spot is not an opening, so
+	// nothing is announced — but the detector now exists and is collecting).
+	on := &App{opSet: true, opLat: 48.0, opLon: 2.0}
+	on.bandOpen.on.Store(true)
+	on.detectBandOpening(spot())
+	if on.bandOpen.det == nil {
+		t.Error("the detector did not run with the watch switched on")
+	}
+}
+
+// Switching the watch off must put the badges out. They fade on a timer fed by
+// spots the detector no longer looks at, so left alone they would stay lit
+// until the next restart.
+func TestClearBandOpeningsPutsTheBadgesOut(t *testing.T) {
+	a := &App{}
+	a.bandOpen.live = map[string]bandopen.Opening{"6m": {Band: "6m", Calls: 9}}
+	a.bandOpen.aliveUntil = map[string]time.Time{"6m": time.Now().Add(time.Hour)}
+	a.bandOpen.det = bandopen.New(bandopen.DefaultConfig())
+	a.bandOpen.last = []bandopen.Opening{{Band: "6m", Calls: 9}}
+
+	a.clearBandOpenings()
+
+	if got := a.GetLiveOpenings(); len(got) != 0 {
+		t.Errorf("a badge stayed lit after the watch was switched off: %v", got)
+	}
+	if a.bandOpen.det != nil {
+		t.Error("the accumulated spot window survived — switching back on would start from a stale burst")
+	}
+	// The history is NOT cleared: those openings really happened.
+	if len(a.GetBandOpenings()) != 1 {
+		t.Error("the remembered openings were thrown away")
+	}
+}
diff --git a/changelog.json b/changelog.json
index a614bf8..430654e 100644
--- a/changelog.json
+++ b/changelog.json
@@ -11,7 +11,7 @@
       "Motorized antennas: each covered band now has its own tune frequency, set in a box under the band in Settings, and that is where the band button in Station Control sends the antenna. Left empty a band keeps its default, and a frequency that is not in its band is refused rather than sent to the elements.",
       "Awards: a single award can now be exported on its own, next to the whole-catalogue export. Sharing one award meant handing over your entire catalogue.",
       "Awards: each reference now has its own validity window, so a reference that ceased to exist counts for QSOs made while it existed and not for later ones. The dates were already stored and were never applied; left empty a reference follows the award's own window.",
-      "DX cluster: the \"No colour on worked\" and \"Colour unworked here\" options are withdrawn from the filter panel and are off for everyone."
+      "Band openings: the watch switch now governs the detection itself. It only ever controlled the extra data sources, so opening banners appeared even for operators who had left the option off; switching it off also puts out any badge still lit."
     ],
     "fr": [
       "Les QSO enregistrés depuis WSJT-X portent désormais la météo spatiale et la distance, comme ceux saisis à la main. Le chemin UDP posait le profil station, le DXCC et les défauts QSL mais ni SFI, ni A, ni K, ni distance — un opérateur en numérique avait donc ces champs vides sur tout son log. La météo spatiale n est posée que sur un contact de moins d un jour : sinon un logiciel qui rediffuse son historique se verrait attribuer les relevés de ce matin sur des contacts du mois dernier.",
@@ -22,7 +22,7 @@
       "Antennes motorisées : chaque bande couverte a désormais sa propre fréquence d accord, saisie dans une case sous la bande dans les Réglages, et c est là que le bouton de bande du Contrôle station envoie l antenne. Laissée vide, une bande garde son défaut, et une fréquence hors de sa bande est refusée plutôt qu envoyée aux éléments.",
       "Diplômes : un diplôme peut désormais être exporté seul, à côté de l export du catalogue complet. Partager un seul diplôme obligeait à livrer tout son catalogue.",
       "Diplômes : chaque référence a désormais sa propre fenêtre de validité, si bien qu une référence qui a cessé d exister compte pour les QSO faits de son vivant et pas pour les suivants. Les dates étaient déjà stockées et n étaient jamais appliquées ; laissée vide, une référence suit la fenêtre du diplôme.",
-      "Cluster DX : les options « Pas de couleur sur les faits » et « Colorer les non faits ici » sont retirées du panneau de filtres et désactivées pour tout le monde."
+      "Ouvertures de bande : l interrupteur de la veille gouverne désormais la détection elle-même. Il ne pilotait que les sources de données supplémentaires, si bien que les bandeaux d ouverture apparaissaient même chez les opérateurs qui avaient laissé l option désactivée ; la désactiver éteint aussi les badges encore allumés."
     ]
   },
   {