I live a sheltered life and had never heard of that but it makes sense -- traveling entrepreneurship at its finest.
I’m honestly just guessing.
My brother runs a large truck stop and “ladies” like to get in where the overnight trucks are parked.
I do know (from briefly working as a pilot for an oil company) that boats with vendors go from oil rig to oil rig in Nigeria and on the Gulf Coast of Texas.
Have seen boats stacked up waiting their turn at port for miles off shore with all sorts of little boats going between them.
Just make a logical deduction.