Really? That's a new one to me.
When I was a dock rat in North Carolina the rats did get a bit of the fuel pie as well we split the meager tips.A very long time ago.
I as well a lot of the broke sailors I knew gave the word CHEAP a new meaning to the docks.Slide in after dark out before first light.Anchor out then come in for 10 gallons of fuel and 30 gallons of water.The salt and pepper shakers kind of resembled restaurant style equipment as well the little packets of sugar.I was 19 then and did not have a penny to spare.Worked as I could then went as far as that money would take me.Ah fond memories.
Now that I am getting back into moving a few boats around I do tip and actually stay at the dock with a reservation if offshore is not inviting.
As said people are people on land or sea.