Using clues he gleaned from the Icelandic Sagas, his experience as a professional navigator, and from his voyages on "Borgunknarren"--a 60' Viking ship replica--Leif K. Karlsen reveals the secrets of Viking navigation. Karlsen has done extensive research on the Viking "sunstone" and "horizon board" and explains how they work. This is an interesting, valuable, and educational contribution to the understanding of the Vikings' success as navigators and seamen.

--Dr. Alf Lunder Knudsen, Editor Emeritus Western Viking

If "cutting edge" can be used in relation to Viking navigation, this information is definitely it. Leif Karlsen is the world's foremost scholar on the Viking sunstone. His well-researched and intelligent work on Viking navigation examines the sagas and combines that information with the experiential and practical research of just trying it out. It's a comprehensive and accessible study that's also a compelling analysis of the secrets of Viking navigators, and their unparalleled success as sea-born explorers.

--Kristine Leander, PhD, Director, Leif Erikson International Foundation

Most navigators have heard of Viking sunstones, but few realize they are more than legend. Leif Karlsen has brought them to life. He shows us how they work--now, and a thousand years ago--and what it was that led the Viking navigators to develop this unique tool for finding the direction to the sun, even when the sun is obscured by clouds or fog.

--David Burch, PhD, Director, Starpath School of Navigation