The Law of the Sea tacitly assumes that the boundaries delimiting mari
time and other spaces on the earth surface are known exactly. This is
clearly unwarranted: like any position on the surface of the earth, ma
ritime boundaries have positional errors associated with them. Yet the
assumption of boundaries being errorless is shared not only amongst t
he lawyers, but amongst the mariners as well. The usual attitude encou
ntered in maritime practice is: yes, there may be some errors in the b
oundaries, but these are so small that they are practically irrelevant
. In the case of trespassing, the only uncertainty ever taken into con
sideration is the uncertainty of the trespasser's position vis-a-vis t
he boundary in question. In this contribution, we are going to discuss
the errors in the boundaries from the technical point of view. We sha
ll try to answer the following questions:1) How large can the errors i
n maritime boundaries be and do they matter? 2) Where are these errors
coming from? 3) What can be done to eliminate the gross errors and ke
ep the systematic errors to a minimum? 4)What can be done with the ran
dom errors?.