Water salutes by the fire crew are regulary done for certain events like plane retiring, or an new airplane delivered and much more. But where does it come from? And why should the fire service do a water salute even if they don't really care about a pilot retiring?
Water salutes are purely ceremonial and have no practical value. There are no confirmed reports on when it started in aviation, but it became common in the 1990's.
Before aviation, this practice started for ships on their inaugural voyages or returning from a long voyage. At New York harbor, jets of water were sprayed from fire boats.
Commonly, water salutes are done for:
- first flight of an airplane
- first or last revenue flight of an airplane
- last flight of a retiring pilot
- carrying a fallen soldier
Mostly, it attracts attention and looks cool without costing a huge amount or having anything to clean up.
Fire Services usually test their equipment weekly. If you give them some notice they will schedule that weeks test to accommodate a special event.
I've seen them hose down the area next to the fire station to please a school trip so I bet its not an issue for them.