The respondent to the "Mayday" asks if they have any maps. he would have asked if they had any charts. Charts are used for navigation, not maps. Although, John had informed him that he was a passenger and the respondent chose to be expedient by using the more generic term "nautical maps" rather than the technical term, so that the passenger would more readily understand him in an emergency situation. He understood that a passenger would be more familiar with the more common term amongst land-lubbers.
Spencer boards the RMS Mauritania to make a radio call. Mauritania was in dry-dock for most of 1920 and half of 1924 to refurbish its engines Half the work was done in the Uk and the last half in France when the UK dockworkers went on strike.
Spencer finds the tug captain dead so calls out a mayday. Another ship answers, asking Spencer if he has a compass and charts but a compass merely tells you direction but not a location on a chart. A sextant would be required in order to find the position. Before the other captain can ask about his the tug hits the ghost ship and he doesn't have the chance to ask.
When Teonna Rainwater is chased up on top of the rock by the wolf, when it lies down the clear print of a modern work boot can be seen between its flank and the rock.
The stockyard manager says to Jack, 'heard some of your hands went off to Hollywood with them Strafford boys to play cowboy in the silent pictures.' However, the term 'silent pictures' would not be used until it was necessary to distinguish them from 'talking pictures' when they were introduced - the earliest being The Jazz Singer in 1927.
The RMS Mauretenia in 1923 was not in service. It also never sailed in East Africa. The real RMS Mauretenia (1906) sailed to the New York from Southampton via Cobh, Ireland. It would not have been possible of Spencer to send a message to Montana via London on the RMS Mauretenia (1906).