This is the second known English edition of Blaeu's 'Zeespiegel', the charts being the same as those in the Dutch edition of 1623.
The 'Zeespiegel' was the second of Blaeu's great pilot guides: the first, 'Het Licht der Zeevaert', was published in various editions and languages between 1608 and 1630. Blaeu's copyright to this work appears to have run out in 1618, and from 1620 Johannes Janssonius was publishing his own counterfeit versions. Blaeu responded to this threat from his rival by publishing the present work in 1623. Three parts bound in one volume (parts 2 and 3 containing 6 books each), folio (345 by 225mm), main and divisional titles with woodcut vignettes, 109 engraved maps, all but 3 double-page, numbered 1-108 with 51bis, 2 other smaller engraved charts in the text, 2 volvelles, woodcut diagrams and coastal profiles in the text, woodcut of ships on titles, the part-title to the fourth book of the second part from the 1625 edition, some light browning and dampstaining, chart 41 supplied, volvelle on C4 lacking pointer.