Well it depends on how big the riverboat is. Usually at least 30 or 20 people.
4 passengers can fit but 3 to be comfortable.
Seven passengers
A small airplane can fit upto 4 passengers.
4 Passengers, one driver. If there is a front bench seat, then you can fit 5 Passengers.
1 driver and 3 passengers
2 crew, 12 passengers.
8
an average of 550 passengers can fit on a passenger plane
12
853
Four
4.