Article 18 : Meaning of passage

1. Passage means navigation through the territorial sea for the purpose
(a) traversing that sea without entering internal waters or calling at
a roadstead or port facility outside internal waters; or
(b) proceeding to or from internal waters or a call at such roadstead
or port facility.
2. Passage shall be continuous and expeditious. However, passage
includes stopping and anchoring, but only in so far as the same are incidental to ordinary navigation or are rendered necessary by force majeure or distress or for the purpose of rendering assistance to persons, ships or aircraft in danger or distress.
Source : UNCLOS