At first sight, the Territorial Sea (Amendment) Order 19981 is an unremarkable instrument. Its explanatory note states that it amends the Schedule to the Territorial Waters Order in Council 19642 ‘by adding a new baseline between the Mull of Kintyre and Laggan, as well as by making minor changes to [three points scheduled in the 1964 Order] which result from the publication of a new, larger scale chart of the area’. In fact, the note is a model of economy of information disguising the difficulties which led to the Order's addition of a further straight baseline, enclosing the Firth if Clyde, to the system of straight baselines starting in the north at Cape Wrath and which, before the above amendment was made, had ended in the south at the Mull of Kintyre. This is the story behind the addition of the new segment. The sketch map indicates the general cartography of the relevant area.