As a child, spending my summers on the shores of the St.Lawrence River, our family could easily tell when a liner was upbound on the river, even before we could see it. We would suddenly begin to get Morse code coming in over our AM radio! This meant a ship with a very powerful transmitter was nearby.
We would then keep an eye out for an upbound liner, as they frequently came close to the shore with the rising tide. Our favourite was the Empress of Scotland because she was the most elegant, and the last of the three stack ships.
Our cottage had a flag pole and we always saluted the liners, but of course we never received an acknowledgement-our flag was too tiny. On one occassion however the Empress of Scotland had just passed our place and we were once again disappointed that it did not respond to our flag salute, when suddenly it signalled three very long blasts of its most impressive steam whitle. We rushed back out to dip the flag again to acknowledge, but at the same instant the ship sounded its single blast.
We were crushed that the ship was saluting some other lucky person a few miles upstream- but the Empress of Scotland was still our favourite ship.