Index: applications/editors/josm/plugins/smed/src/org/openstreetmap/josm/plugins/seamapeditor/seamarks/SeaMark.java
===================================================================
--- applications/editors/josm/plugins/smed/src/org/openstreetmap/josm/plugins/seamapeditor/seamarks/SeaMark.java	(revision 35264)
+++ applications/editors/josm/plugins/smed/src/org/openstreetmap/josm/plugins/seamapeditor/seamarks/SeaMark.java	(revision 35265)
@@ -2703,5 +2703,5 @@
             UndoRedoHandler undoRedo = UndoRedoHandler.getInstance();
             for (String str : node.getKeys().keySet()) {
-                if (str.trim().matches("^seamark:\\S+")) {
+                if ((str.trim().matches("^seamark:\\S+")) || (str.trim().matches("^seamark$"))) {
                     undoRedo.add(new ChangePropertyCommand(node, str, null));
                 }