Repel boarders

This morning I was woken at 7:30 by Andrea shouting "Get out, get out".  An unusually vivid dream, I thought, and then realized she was sitting up and shouting at an apparition in the porthole.  There, silhouetted against the dawning sky, was a black cat creeping into our cabin.  It only woke Andrea because it was on the bookcase above her side of the bed, looking down and dripping cold seawater on her head.  It was totally soaked so it must have swum aboard.  It looked particularly scary with its hair all plastered down, the kind of outline they use to depict evil cats in cartoons.
 
It left pretty quickly when it realized Andrea wasn't ready for her morning shower just yet.  We hurried up on deck to see where it had gone.  There are several water trails, the heaviest trail leading up from the sugar scoop across the cockpit and to our inboard porthole.  We can't see any trail obviously leaving the boat.  It is low tide right now so it would have to scale a smooth 9 ft concrete wall to get back to dry land, but maybe it managed it.  Or perhaps it swam or leaped to a neighboring boat.
 
On another subject, I can't believe that last night we pulled a load of flags attached to a flimsy bit of string using our precious spinnaker halyard.  If the flag string should break (and we pulled it nice and tight so the flags are not droopy) then the halyard would come snaking through the blocks and down the inside of the mast.  Then we would have to try and re-thread it from the top of the mast.  First thing this morning we will be attaching a safety line to the halyard.