During Christmas season, evergreen trees were hoisted to the masthead or yardarms. Sometimes they were decorated with coloured lights. They could be seen for many miles. Being out to sea for long periods of time I bet that this would bring a piece of home to them.
SIGNALS FOR SPECIAL OCCASIONS
The flying of flags to celebrate an occasion such as holidays like Christmas or an event is one of the oldest customs in the navy. It probably stems from the days when flags and trophies captured from the enemy were displayed as a sign of victory. When a ship is dressed , she flies her ensign, jack, masthead ensigns and dressing lines. Below is a picture of a fully dressed ship:
Below is a picture of 3 sailors getting ready to string the flags:
A flag-hoisting team usually included two or three signalmen. Their job was to clip the flags together, attach them to the signal halyard and hoist them up the mast. This may sound simple but to achieve accuracy and speed it took lots of practice and teamwork. Stowing the flags was almost as important as hoisting them. There was always competition among ships to see who could hoist flags the fastest. Normally these sailors would be in their work uniforms.