Which hull length is used in the Agincourt reconstruction?

Do the proposed Agincourt dimensions refer to overall length, waterline length, or length between perpendiculars?

They refer to overall length. Estimates of about 210 metres remain uncertain, and the larger armament explored in a game depends on the assumed hull.

Overall length, waterline length, and length between perpendiculars measure different parts of a hull, and waterline length also varies with draft. The comparison here uses overall length. Estimates reaching about 210 metres are mentioned for Agincourt, but that figure remains uncertain. Such an increase could create space for a larger armament. A game exercise fitted eight 18-inch guns in four twin turrets into a longer hull; it does not establish that this was the historical design.