This photo was taken from Tuckurimba on the North Arm of the Richmond River (now Wilson River).

The boat is the Captain T Fenwick and the young lads have just enlisted at Lismore and are on their way to Ballina to get a steamer to Sydney and head off to WWI. For some young soldiers, this would be their last photo. 

Someone on board, having spotted George on the wharf with his camera, has lined the lads up with their guns shouldered.

Source: Australian Maritime History