Lieutenant-Governor of the Isle of Man from 1863 to 1882.

The Manx Society listed him as its President while he held the office. His long tenure covers the period in which the Island's modern institutions took their shape, and Manx writers use his name as the marker for the years in question.

One episode belongs to him particularly. An earlier proposal to absorb the Manx diocese had been beaten off when the Manx clergy and the Manx bar roused themselves against it and the government of the day gave way. Years afterwards, in Loch's time, the project was revived, the government then proposing to unite the see of Sodor and Man with the new diocese of Liverpool, and to sweeten the change by applying a large part of the see's revenues to improving the incomes of the parochial clergy.

He went on to govern elsewhere. He was appointed Lieutenant-Governor of Victoria on 10 April 1884 and arrived at Melbourne with Lady Loch and his family on 15 July, where deputations representing the Manx residents presented addresses of welcome. He wrote from Melbourne wishing The Manx Note Book success.