diff --git a/src/water_map.h b/src/water_map.h
--- a/src/water_map.h
+++ b/src/water_map.h
@@ -94,7 +94,7 @@ static inline WaterTileType GetWaterTile
  */
 static inline bool HasTileWaterClass(TileIndex t)
 {
-	return IsTileType(t, MP_WATER) || IsTileType(t, MP_STATION) || IsTileType(t, MP_INDUSTRY) || IsTileType(t, MP_OBJECT);
+	return IsTileType(t, MP_WATER) || IsTileType(t, MP_STATION) || IsTileType(t, MP_INDUSTRY) || IsTileType(t, MP_OBJECT) || IsTileType(t, MP_TREES);
 }
 
 /**
@@ -204,7 +204,7 @@ static inline bool IsCoast(TileIndex t)
  */
 static inline bool IsCoastTile(TileIndex t)
 {
-	return IsTileType(t, MP_WATER) && IsCoast(t);
+	return (IsTileType(t, MP_WATER) && IsCoast(t)) || (IsTileType(t, MP_TREES) && GetWaterClass(t) != WATER_CLASS_INVALID);
 }
 
 /**