Index: trunk/data/tagchecker.cfg
===================================================================
--- trunk/data/tagchecker.cfg	(revision 5267)
+++ trunk/data/tagchecker.cfg	(revision 5273)
@@ -133,5 +133,5 @@
 *    : W : stream               == * && waterway != *                                  # stream without waterway
 *    : W : intermittent         == * && waterway != *                                  # intermittent without waterway
-*    : W : boat                 == * && waterway != *                                  # boat without waterway
+*    : W : boat                 == * && waterway != * && natural != water              # boat without waterway / natural=water
 *    : W : length_unit          == * && waterway != *                                  # length_unit without waterway
 *    : W : llid                 == * && waterway != *                                  # llid without waterway