Dutch historian Francois Valentyn’s map of 1724, replete with depth markings between Taiwan and mainland China, accentuates the strategic value of the strait.
Joannes van Braam and Gerard onder de Linden
1724
<a rel="nofollow" class="external text" href="http://taiwantoday.tw/ct.asp?xItem=188482&amp;ctNode=428"><i>Taiwan Today</i></a>, a digitization of François Valentiyn's <i>Oud en Nieuw Oost-Indien</i>, Vol. IV, Pl. 1.