For example the median expected annual pay for a typical Psychiatrist in the United States is $205,390, so 50% of the people who perform the job of Psychiatrist in the United States are expected to make less than $205,390.
Lightering (also called lighterage) is the process of transferring cargo between vessels of different sizes, usually between a barge and a bulker or oil tanker. Lightering is undertaken to reduce a vessel's draft in order to enter port facilities which cannot accept very large ocean-going vessels.
A semi truck gasoline tanker holds 9,000 gallons, give or take. The capacity is usually controlled by the 80,000 lb gross weight limit for trucks in the US. (I can't speak for other parts of the world.) A gallon of gasoline weighs about 7 lbs, and the truck weighs quite a bit itself, so you don't see liquid hydrocarbon tanks exceed 10,000 gallons.