The loss of Admiral Sir Clowdisley Shovel with several ships on the Bishop and Clerks on 23 October 1707, and the subsequent attribution of the disaster by Captain Sir William Jumper of the Lenox, 70 guns, to defective compasses, led to the compiling of reports on these instruments by the Commissioners at Chatham and Portsmouth, by order of the Navy Board. Captain George St. Lo, the Commissioner at Chatham, was at this time about fifty years of age. We first hear of him being appointed a Lieutenant of the Phoenix, 42, in 1678; he was made Post into the Dartmouth, 30, in 1682. With the three years qualifying service necessary before he obtained his first commission he must have had fourteen years almost continuously at sea before his career was cut short by his being severely wounded and taken prisoner when he had to surrender the sorely battered Portsmouth, 46, to superior French force in 1689. While a prisoner of war he took the opportunity to study the dockyard methods of his captors and this, with his reputation for steadfast opposition to all corruption, made him particularly suited to fill the post of commissioner in a dockyard. In 1707 he had already been five years at Chatham, following eight in Plymouth dockyard.