Sorry, Captain Dave, but I think this photo is beyond rescue.
I don't know what camera you work with. The size looks like it might be a compact digital camera? Those often start to show horrific amounts of noise at only 200 ISO, and 400 ISO just produce photos ... erm ... for the bin (my Powershot does this!). I appreciate that the foggy day you had (which you tried to capture here) was quite dark. Which is why either you yourself - or the camera in your stead if it was an Auto ISO - suggested you crank up the iso much as not to get too long shutter speeds. Well ... either don't DO it with a compact camera of the kind, i.e. don't push the ISO any higher than 100, or don't LET the camera do it, i.e. take off auto ISO. Get yourself a tripod (or a bean bag, or find yourself a wall, a bucket, a box, whatever) as support, and allow for longer shutter speeds in dark(er) surroundings. You might be happier with the outcome in the end.