The map in the 16.28 link says early 1880s although a previous reference I saw said that Galston started drawing the charts in the 1870s. I doubt that the times would have altered very much for decades and certainly not for hundreds of years prior to steam being widely introduced. Remember the servicemen, taken for granted then as well, would not be travelling on the best or indeed fastest or safest vessels. My father's uncle( his father's youngest brother) was lost on a troop ship travelling to India. The family always maintain that he was thrown overboard by the officers as punishment for fighting and already having stowed away on a ship from India to get back to England.