diff --git a/backend/src/main/java/gc/mda/kcg/collector/osint/OsintCollector.java b/backend/src/main/java/gc/mda/kcg/collector/osint/OsintCollector.java
index f9eb073..e58b2b9 100644
--- a/backend/src/main/java/gc/mda/kcg/collector/osint/OsintCollector.java
+++ b/backend/src/main/java/gc/mda/kcg/collector/osint/OsintCollector.java
@@ -118,6 +118,8 @@ public class OsintCollector {
                 if (articleUrl == null || title == null || title.isBlank()) continue;
 
                 if (osintFeedRepository.existsBySourceAndSourceUrl("gdelt", articleUrl)) continue;
+                if (osintFeedRepository.existsByRegionAndTitleAndCollectedAtAfter(
+                        region, title, Instant.now().minus(24, ChronoUnit.HOURS))) continue;
 
                 String seendate = article.path("seendate").asText(null);
                 Instant publishedAt = parseGdeltDate(seendate);
@@ -182,6 +184,8 @@ public class OsintCollector {
 
                 if (link == null || title == null || title.isBlank()) continue;
                 if (osintFeedRepository.existsBySourceAndSourceUrl(sourceName, link)) continue;
+                if (osintFeedRepository.existsByRegionAndTitleAndCollectedAtAfter(
+                        region, title, Instant.now().minus(24, ChronoUnit.HOURS))) continue;
 
                 Instant publishedAt = parseRssDate(pubDate);
 
diff --git a/backend/src/main/java/gc/mda/kcg/domain/osint/OsintFeedRepository.java b/backend/src/main/java/gc/mda/kcg/domain/osint/OsintFeedRepository.java
index 95cf034..b87a231 100644
--- a/backend/src/main/java/gc/mda/kcg/domain/osint/OsintFeedRepository.java
+++ b/backend/src/main/java/gc/mda/kcg/domain/osint/OsintFeedRepository.java
@@ -9,5 +9,7 @@ public interface OsintFeedRepository extends JpaRepository<OsintFeed, Long> {
 
     boolean existsBySourceAndSourceUrl(String source, String sourceUrl);
 
+    boolean existsByRegionAndTitleAndCollectedAtAfter(String region, String title, Instant since);
+
     List<OsintFeed> findByRegionAndCollectedAtAfterOrderByPublishedAtDesc(String region, Instant since);
 }
diff --git a/frontend/src/components/layers/ShipLayer.tsx b/frontend/src/components/layers/ShipLayer.tsx
index f82a686..7049302 100644
--- a/frontend/src/components/layers/ShipLayer.tsx
+++ b/frontend/src/components/layers/ShipLayer.tsx
@@ -359,6 +359,7 @@ export function ShipLayer({ ships, militaryOnly, koreanOnly, hoveredMmsi, focusM
   const [selectedMmsi, setSelectedMmsi] = useState<string | null>(null);
   const [imageReady, setImageReady] = useState(false);
   const highlightKorean = !!koreanOnly;
+  const prevHoveredRef = useRef<string | null>(null);
 
   // focusMmsi로 외부에서 모달 열기
   useEffect(() => {
@@ -399,7 +400,6 @@ export function ShipLayer({ ships, militaryOnly, koreanOnly, hoveredMmsi, focusM
         isMil: isMilitary(ship.category) ? 1 : 0,
         isKorean: ship.flag === 'KR' ? 1 : 0,
         isCheonghae: ship.mmsi === '440001981' ? 1 : 0,
-        isHovered: ship.mmsi === hoveredMmsi ? 1 : 0,
         heading: ship.heading,
       },
       geometry: {
@@ -408,7 +408,26 @@ export function ShipLayer({ ships, militaryOnly, koreanOnly, hoveredMmsi, focusM
       },
     }));
     return { type: 'FeatureCollection' as const, features };
-  }, [filtered, hoveredMmsi]);
+  }, [filtered]);
+
+  // hoveredMmsi 변경 시 feature-state로 hover 표시 (GeoJSON 재생성 없이)
+  useEffect(() => {
+    if (!map) return;
+    const m = map.getMap();
+    if (!m.getSource('ships-source')) return;
+
+    if (prevHoveredRef.current != null) {
+      try {
+        m.removeFeatureState({ source: 'ships-source', id: prevHoveredRef.current });
+      } catch { /* source not ready */ }
+    }
+    if (hoveredMmsi) {
+      try {
+        m.setFeatureState({ source: 'ships-source', id: hoveredMmsi }, { hovered: true });
+      } catch { /* source not ready */ }
+    }
+    prevHoveredRef.current = hoveredMmsi ?? null;
+  }, [map, hoveredMmsi]);
 
   // Register click and cursor handlers
   useEffect(() => {
@@ -447,12 +466,12 @@ export function ShipLayer({ ships, militaryOnly, koreanOnly, hoveredMmsi, focusM
 
   return (
     <>
-      <Source id="ships-source" type="geojson" data={shipGeoJson}>
+      <Source id="ships-source" type="geojson" data={shipGeoJson} promoteId="mmsi">
         {/* Hovered ship highlight ring */}
         <Layer
           id="ships-hover-ring"
           type="circle"
-          filter={['==', ['get', 'isHovered'], 1]}
+          filter={['boolean', ['feature-state', 'hovered'], false]}
           paint={{
             'circle-radius': 18,
             'circle-color': 'rgba(255, 255, 255, 0.1)',
@@ -474,27 +493,26 @@ export function ShipLayer({ ships, militaryOnly, koreanOnly, hoveredMmsi, focusM
             'circle-stroke-opacity': highlightKorean ? 1 : 0.6,
           }}
         />
-        {/* Korean ship label (only when highlighted) */}
-        {highlightKorean && (
-          <Layer
-            id="ships-korean-label"
-            type="symbol"
-            filter={['==', ['get', 'isKorean'], 1]}
-            layout={{
-              'text-field': ['get', 'name'],
-              'text-size': 9,
-              'text-offset': [0, 2.2],
-              'text-anchor': 'top',
-              'text-allow-overlap': false,
-              'text-font': ['Open Sans Regular'],
-            }}
-            paint={{
-              'text-color': '#00e5ff',
-              'text-halo-color': 'rgba(0,0,0,0.8)',
-              'text-halo-width': 1,
-            }}
-          />
-        )}
+        {/* Korean ship label — always mounted, visibility으로 제어 */}
+        <Layer
+          id="ships-korean-label"
+          type="symbol"
+          filter={['==', ['get', 'isKorean'], 1]}
+          layout={{
+            'visibility': highlightKorean ? 'visible' : 'none',
+            'text-field': ['get', 'name'],
+            'text-size': 9,
+            'text-offset': [0, 2.2],
+            'text-anchor': 'top',
+            'text-allow-overlap': false,
+            'text-font': ['Open Sans Regular'],
+          }}
+          paint={{
+            'text-color': '#00e5ff',
+            'text-halo-color': 'rgba(0,0,0,0.8)',
+            'text-halo-width': 1,
+          }}
+        />
         {/* Main ship triangles */}
         <Layer
           id="ships-triangles"