Vesper makes the maps and charts that every ship on the Logathriad Sea steers by, and the names on Rann's most accurate maps of the world are theirs. They have made them for about thirty years.

Vesper goes out for a season and comes back with a new chart. Their books carry distances, depths, landmarks, and headings.

Every port has someone who claims to have met Vesper, and all accounts differ in the details.