Over Open Sights traces the early development of naval wargaming in the Royal Navy between 1873 and 1904. It is part of a series by the History of Wargaming Project documenting early wargaming.

The book opens with a foreword by the well-known author and game designer, Larry Bond. Next is a reflective essay about the position of naval wargaming within the hobby.
The heart of the book is the reproduction of the early wargames, with period commentary from various RUSI sessions.
The naval wargames included are:
Lieutenant Castle R.N.: The Game of Naval Tactics (1873)
Captain Colomb R.N.: The Duel: A Naval Wargame (1879)
Lieutenant H. Chamberlain R.N.: Game of Naval Blockade (1888)
The Launch of the Fred Jane Naval Wargame at RUSI (1898)
The First Edition of The Fred Jane Naval Wargame (1898)
The book also includes further material on the Fred Jane Wargame.