Otters are a personal favourite of mine and there is a great deal of satisfaction to be had from photographing them in the wild. However, in order to capture the best images it is vital, as in all genres of nature photography, be it mammals, birds, plants or insects etc to ensure that absolute priority is giving to the welfare of the subject. Knowing how to photograph any particular specie relies just as much on good field craft as it does on having suitable photography skill and equipment. Knowledge of your intended subject will always be beneficial, and knowing when to walk away at the fist sign of distress in the subject is paramount.
This particular otter image was taken in the early morning after careful observation of the otter over a couple of hours, followed by a gentle approach and then patiently waiting for the right moment.
I lay, rather uncomfortably, on the rocky shore to get a fairly low level viewpoint with the lens resting on a beanbag placed on a rock to keep the camera as steady as possible.
Fortunately, my low hidden position meant the otter returned to this rock a couple of times within a 20 minute period with catches of fish and crab. During this time I was able to take several different images as he fed totally unaware of my presence.
The otter image (above) was taken with a Canon 1D mkIII and a 500mm f4 lens set to f5.6, due to the fairly dull overcast conditions I chose a relatively high speed of ISO 1250 to ensure a reasonably fast shutter speed of 1/250th second.