diff --git a/backend/src/Controller/SpotScoreController.php b/backend/src/Controller/SpotScoreController.php
index 70f15ae..2d240f8 100644
--- a/backend/src/Controller/SpotScoreController.php
+++ b/backend/src/Controller/SpotScoreController.php
@@ -107,7 +107,10 @@ class SpotScoreController extends AbstractController
              JOIN sargassum_observation o  ON o.id  = f.source_observation_id
              WHERE f.source_observation_id = (
                  SELECT o2.id FROM sargassum_observation o2
-                 INNER JOIN sargassum_forecast ff ON ff.source_observation_id = o2.id
+                 INNER JOIN sargassum_forecast ff ON ff.source_observation_id = o2.id,
+                            coastal_point cp3
+                 WHERE cp3.id = :spotId
+                   AND ST_Distance(o2.geometry::geography, cp3.geometry::geography) < 300000
                  ORDER BY o2.detected_at DESC LIMIT 1
              )
              ORDER BY f.time_horizon ASC',
@@ -226,7 +229,10 @@ class SpotScoreController extends AbstractController
                  FROM sargassum_observation o
                  WHERE o.id = (
                      SELECT o2.id FROM sargassum_observation o2
-                     INNER JOIN sargassum_forecast ff ON ff.source_observation_id = o2.id
+                     INNER JOIN sargassum_forecast ff ON ff.source_observation_id = o2.id,
+                                coastal_point cp3
+                     WHERE cp3.id = :spotId
+                       AND ST_Distance(o2.geometry::geography, cp3.geometry::geography) < 300000
                      ORDER BY o2.detected_at DESC LIMIT 1
                  )
              ) dump
diff --git a/backend/src/Service/Forecast/ImpactScoreService.php b/backend/src/Service/Forecast/ImpactScoreService.php
index 783d104..d6c6ee4 100644
--- a/backend/src/Service/Forecast/ImpactScoreService.php
+++ b/backend/src/Service/Forecast/ImpactScoreService.php
@@ -267,6 +267,25 @@ class ImpactScoreService
     /** @param array{score: int, level: string, distance: float|null, density: float, trend: string, etaHours: int|null} $data */
     private function persistScore(CoastalPoint $spot, array $data): void
     {
+        // "L'observation la plus proche gagne" : ne pas écraser un score avec une distance
+        // plus grande que le score actuel, sauf si celui-ci a plus de 6h (stale).
+        if ($data['distance'] !== null) {
+            $current = $this->connection->fetchAssociative(
+                'SELECT distance_to_nearest_sargassum AS dist, timestamp
+                 FROM impact_score WHERE coastal_point_id = :id ORDER BY timestamp DESC LIMIT 1',
+                ['id' => (string) $spot->getId()]
+            );
+            if ($current !== false && $current['dist'] !== null) {
+                $ageSeconds = (new \DateTimeImmutable())->getTimestamp()
+                            - (new \DateTimeImmutable($current['timestamp']))->getTimestamp();
+                $isStale    = $ageSeconds > 21_600; // 6h
+                $isCloser   = $data['distance'] < (float) $current['dist'];
+                if (!$isStale && !$isCloser) {
+                    return; // garder le score de l'observation plus proche
+                }
+            }
+        }
+
         $s = new ImpactScore();
         $s->setCoastalPoint($spot);
         $s->setScore($data['score']);