diff -r b3849a19d137 -r e737405b06dd src/ai/api/ai_marine.hpp
--- a/src/ai/api/ai_marine.hpp	Tue Apr 08 07:19:02 2008 +0000
+++ b/src/ai/api/ai_marine.hpp	Tue Apr 08 07:24:23 2008 +0000
@@ -6,6 +6,7 @@
 #define AI_MARINE_HPP
 
 #include "ai_object.hpp"
+#include "ai_error.hpp"
 
 /**
  * Class that handles all marine related functions.
@@ -14,6 +15,14 @@
 public:
 	static const char *GetClassName() { return "AIMarine"; }
 
+	enum ErrorMessages {
+		/** Base for marine related errors */
+		ERR_MARINE_BASE = AIError::ERR_CAT_MARINE << AIError::ERR_CAT_BIT_SIZE,
+
+		/** Infrastructure must be built on water */
+		ERR_MARINE_MUST_BE_BUILT_ON_WATER,                  // [STR_3801_MUST_BE_BUILT_ON_WATER]
+	};
+
 	/**
 	 * Checks whether the given tile is actually a tile with a water depot.
 	 * @param tile The tile to check.
@@ -59,6 +68,9 @@
 	 * @param tile The tile where the water depot will be build.
 	 * @param vertical If true, depot will be vertical, else horizontal.
 	 * @pre AIMap::IsValidTile(tile).
+	 * @exception AIError::ERR_AREA_NOT_CLEAR
+	 * @exception AIError::ERR_SITE_UNSUITABLE
+	 * @exception AIMarine::ERR_MARINE_MUST_BE_BUILT_ON_WATER
 	 * @return Whether the water depot has been/can be build or not.
 	 */
 	static bool BuildWaterDepot(TileIndex tile, bool vertical);
@@ -67,6 +79,10 @@
 	 * Builds a dock where tile is the tile still on land.
 	 * @param tile The tile still on land of the dock.
 	 * @pre AIMap::IsValidTile(tile).
+	 * @exception AIError::ERR_AREA_NOT_CLEAR
+	 * @exception AIError::ERR_SITE_UNSUITABLE
+	 * @exception AIStation::ERR_STATION_TOO_CLOSE_TO_ANOTHER_STATION
+	 * @exception AIStation::ERR_STATION_TOO_MANY_STATIONS
 	 * @return Whether the dock has been/can be build or not.
 	 */
 	static bool BuildDock(TileIndex tile);
@@ -75,6 +91,9 @@
 	 * Builds a buoy on tile.
 	 * @param tile The tile where the buoy will be build.
 	 * @pre AIMap::IsValidTile(tile).
+	 * @exception AIError::ERR_AREA_NOT_CLEAR
+	 * @exception AIError::ERR_SITE_UNSUITABLE
+	 * @exception AIStation::ERR_STATION_TOO_MANY_STATIONS
 	 * @return Whether the buoy has been/can be build or not.
 	 */
 	static bool BuildBuoy(TileIndex tile);
@@ -83,6 +102,8 @@
 	 * Builds a lock on tile.
 	 * @param tile The tile where the lock will be build.
 	 * @pre AIMap::IsValidTile(tile).
+	 * @exception AIError::ERR_LAND_SLOPED_WRONG
+	 * @exception AIError::ERR_SITE_UNSUITABLE
 	 * @return Whether the lock has been/can be build or not.
 	 */
 	static bool BuildLock(TileIndex tile);
@@ -91,6 +112,10 @@
 	 * Builds a canal on tile.
 	 * @param tile The tile where the canal will be build.
 	 * @pre AIMap::IsValidTile(tile).
+	 * @exception AIError::ERR_AREA_NOT_CLEAR
+	 * @exception AIError::ERR_LAND_SLOPED_WRONG
+	 * @exception AIError::ERR_OWNED_BY_ANOTHER_COMPANY
+	 * @exception AIError::ERR_ALREADY_BUILT
 	 * @return Whether the canal has been/can be build or not.
 	 */
 	static bool BuildCanal(TileIndex tile);
@@ -99,6 +124,7 @@
 	 * Removes a water depot.
 	 * @param tile Any tile of the water depot.
 	 * @pre AIMap::IsValidTile(tile).
+	 * @exception AIError::ERR_OWNED_BY_ANOTHER_COMPANY
 	 * @return Whether the water depot has been/can be removed or not.
 	 */
 	static bool RemoveWaterDepot(TileIndex tile);
@@ -107,6 +133,7 @@
 	 * Removes a dock.
 	 * @param tile Any tile of the dock.
 	 * @pre AIMap::IsValidTile(tile).
+	 * @exception AIError::ERR_OWNED_BY_ANOTHER_COMPANY
 	 * @return Whether the dock has been/can be removed or not.
 	 */
 	static bool RemoveDock(TileIndex tile);
@@ -115,6 +142,7 @@
 	 * Removes a buoy.
 	 * @param tile Any tile of the buoy.
 	 * @pre AIMap::IsValidTile(tile).
+	 * @exception AIError::ERR_OWNED_BY_ANOTHER_COMPANY
 	 * @return Whether the buoy has been/can be removed or not.
 	 */
 	static bool RemoveBuoy(TileIndex tile);
@@ -123,6 +151,7 @@
 	 * Removes a lock.
 	 * @param tile Any tile of the lock.
 	 * @pre AIMap::IsValidTile(tile).
+	 * @exception AIError::ERR_OWNED_BY_ANOTHER_COMPANY
 	 * @return Whether the lock has been/can be removed or not.
 	 */
 	static bool RemoveLock(TileIndex tile);
@@ -131,6 +160,7 @@
 	 * Removes a canal.
 	 * @param tile Any tile of the canal.
 	 * @pre AIMap::IsValidTile(tile).
+	 * @exception AIError::ERR_OWNED_BY_ANOTHER_COMPANY
 	 * @return Whether the canal has been/can be removed or not.
 	 */
 	static bool RemoveCanal(TileIndex tile);