diff --git a/apps/web/src/widgets/map3d/hooks/useZonesLayer.ts b/apps/web/src/widgets/map3d/hooks/useZonesLayer.ts
index 19b143e..6215356 100644
--- a/apps/web/src/widgets/map3d/hooks/useZonesLayer.ts
+++ b/apps/web/src/widgets/map3d/hooks/useZonesLayer.ts
@@ -12,6 +12,33 @@ import type { BaseMapId, MapProjectionId } from '../types';
 import { kickRepaint, onMapStyleReady } from '../lib/mapCore';
 import { guardedSetVisibility } from '../lib/layerHelpers';
 
+/** Globe tessellation에서 vertex 65535 초과를 방지하기 위해 좌표 수를 줄임.
+ *  수역 폴리곤(해안선 디테일 2100+ vertex)이 globe에서 70,000+로 폭증하므로
+ *  ring당 최대 maxPts개로 서브샘플링. 라벨 centroid에는 영향 없음. */
+function simplifyZonesForGlobe(zones: ZonesGeoJson): ZonesGeoJson {
+  const MAX_PTS = 60;
+  const subsample = (ring: GeoJSON.Position[]): GeoJSON.Position[] => {
+    if (ring.length <= MAX_PTS) return ring;
+    const step = Math.ceil(ring.length / MAX_PTS);
+    const out: GeoJSON.Position[] = [ring[0]];
+    for (let i = step; i < ring.length - 1; i += step) out.push(ring[i]);
+    out.push(ring[0]); // close ring
+    return out;
+  };
+  return {
+    ...zones,
+    features: zones.features.map((f) => ({
+      ...f,
+      geometry: {
+        ...f.geometry,
+        coordinates: f.geometry.coordinates.map((polygon) =>
+          polygon.map((ring) => subsample(ring)),
+        ),
+      },
+    })),
+  };
+}
+
 export function useZonesLayer(
   mapRef: MutableRefObject<maplibregl.Map | null>,
   projectionBusyRef: MutableRefObject<boolean>,
@@ -61,11 +88,13 @@ export function useZonesLayer(
       if (!map.isStyleLoaded()) return;
 
       try {
+        // globe: 서브샘플링된 데이터로 vertex 폭증 방지, mercator: 원본 데이터
+        const sourceData = projection === 'globe' ? simplifyZonesForGlobe(zones) : zones;
         const existing = map.getSource(srcId) as GeoJSONSource | undefined;
         if (existing) {
-          existing.setData(zones);
+          existing.setData(sourceData);
         } else {
-          map.addSource(srcId, { type: 'geojson', data: zones } as GeoJSONSourceSpecification);
+          map.addSource(srcId, { type: 'geojson', data: sourceData } as GeoJSONSourceSpecification);
         }
 
         const style = map.getStyle();