A mate of mine was at sea with 'Manchester Lines' sailing between M/cr and Canada.
On one of many trips they were carrying a cargo of Margerine. My mates job as they approached the unloading port,Montreal,was to turn on steam to heating coils in the tanks of Margerine to make it fluid enough to pump out of the tanks. He was a prodidgeous drinker and on approaching Montreal he operated the Steam Valves and also the off-loading pumps and the off-loading valves.
The result was a 15 mile long yellow stripe along the St Lawrence Seaway. It made the headlines on all the TV stations news