* Naval Tactics: In naval battles, firing a volley across the bow of an enemy ship was a tactic used as a warning. The goal was to show force without engaging in full-scale combat. It was a way to demonstrate dominance and potentially force the other ship to change course or comply with demands.
* Historical Evidence: While an exact date is hard to pinpoint, the phrase appears in various historical records and literature from the 18th century onwards. For example, it's found in naval accounts from the Napoleonic Wars and in nautical fiction of that era.
However, the phrase itself may be older, potentially dating back to the 16th or 17th century. It's possible that earlier forms of naval warfare employed similar tactics with cannons, and the phrase evolved to reflect the practice.
To sum up: The exact origin of the phrase "volley across the bow" is difficult to pinpoint, but it likely arose in the 18th century, reflecting the naval tactics of that era.