Mary Grant Bruce 
From Billabong to London [PDF ebook] 
(Illustrated Edition)

Norah Linton can hardly believe she is included in the plan to sail to England. It is 1914. World War One has begun and both Jim and Wally are eager to enlist. Wally, however, is too young to sign up in Australia so together with the Linton family, they sail to England embarking on a perilous wartime voyage. On the boat they experience a naval battle first hand. Who is signalling from a porthole at night and what happens when a German cruiser attacks the ship?