I have updated my blog with details of my recent attempt to capture an otter on trail camera. The camera is an old Acorn camera. It has seen two years of use, was second hand when I purchased it, and the door flap to access the on/off switch is held on with insulation tape. This camera has been out in all weathers and is still going strong. I recommend them. It's the Acorn 5210 model.
http://moochersmoor.blogspot.co.uk/2017/04/tame-valley-otter.html
http://moochersmoor.blogspot.co.uk/2017/04/tame-valley-otter.html