Many thanks all for your comments
and the links for the Loch Quoich monster.
To answer the response of concern, I completely understand it!
Without my experience in different seas and some rather difficult situations in the past (I am also an experienced scuba diver) I think I would not have tried it. I guess like hill walking you sometimes have to check your experience and act accordingly. Swimming is something I am a lot more experienced like for example rock climbing, which in a million years I would do solo.
So to those out there who want to try he same, be assured that you are a good swimmer and know what to do when you get into difficulties.