Steve and Cynthia have pointed out just how testy customs and airtraffic
control can be about ocean dipping. Well, I don't have my books in
front of me, but I seem to remember that most planets will allow ocean
dipping.
Admittedly there may be cases of what I call 'UltraLaw', where
the starport either has been bribed by the fuel refining companies, or
the port is a company and needs to show a profit in its fuel selling
account books. Or maybe the government is just excessive.
In these cases ocean dipping will not be allowed, but I would
say, that if you call the tower and request a vector for ocean dipping,
they will allow access. At higher law levels they may require the ship
be searched first in case of smuggling, but remember that the vector is
to be assigned by the tower, not the ship, they may be allowed to dip
fuel from a location just off the bow of a coast guard cutter.
The US is not a case of 'UltraLaw' yet. You can still fly without
a flight plan, land anywhere you want to, refuel from anywhere you want to.
Admittedly, there are Coast Guard planes out there watching for 'special
cargo' DC-3 Dakotas headed north from Columbia, but once they land in the
US they can pretty much do as they please. Thus, I would say, that once
your cargo has gone through coustoms, chances are you can land anywhere
you want to if you clear it with the Tower. (I seem to remember a planet
in the Trav Adventure that required special forms to do so, but the planet
was a Huge Beaurocracy ie 'UltraLaw').
There is also the case of desert or near desert planets. I believe
the old Spinward Marches Supplement said Dipping was not allowed on planets
with a hydrographic percentage of 30% or less. (It might be 40%)
I think that the Soviet Frontal Aviation and the attendant Soviet
Beaurocracy is a good example of 'UltraLaw'. (I'm not sure, but the last
I heard that young German pilot who landed in Red Square is going to be
there for life...)
Scott S. Kellogg