AbstractWith increasing pressures being placed on developing offshore resources coastal states are faced with negotiating maritime boundaries with neighboring states. Because of the geographical uniqueness of each boundary region no precise and universally accepted delimitation rules have ever been established. Over 280 maritime boundaries have yet to be negotiated. Regardless of the agreed‐upori boundary methodology negotiators should include in the agreement enough technical information so as to avoid later disputes. This paper discusses a number of these technical issues including types of lines, charts, datums, and spheroids.