The American coauthor of a new book on the military defences of Bermuda from 1612 to 1995 is to give a lecture at the Bermuda Underwater Exploration Institute tomorrow.

Terry McGovern, who helped develop the National Museum of Bermuda, had his interest sparked in the island’s fortifications when he first visited the island in 1970.

He has cowritten the book Defences of Bermuda, 1612-1995 with the museum’s former executive director Ed Harris.

Mr McGovern said the defensive works were “some of the best in the world”.

His lecture, The Coastal Defences of the Western Atlantic during World War Two, will focus on the British, Canadian and American efforts to build and man coastal defences during 1939 to 1945.

He said there will be a special focus on the defence line running from Newfoundland to Puerto Rico, with an emphasis on Bermuda as the war effort transformed the island.

The defences were constructed to deal with German surface warships and U-boats in the Battle for the Atlantic.

Mr McGovern shares an interest in military fortifications with Mr Harris, who he met in 1989 while organising a tour in Bermuda.

Mr McGovern said: “I have been studying modern fortifications, especially American defences, since the 1980s, as a hobby. As well as publishing and editing over a dozen books and journals, I have tended to focus on American defences located outside the continental USA.”

He has studied defence networks in Panama, the Philippines, Newfoundland, Hawaii, and Bermuda.

During Mr McGovern’s time in Bermuda, he worked with Mr Harris and then Curator of Forts Lance Furbert, who arranged for him to visit 90 forts and batteries.

Mr McGovern said: “It is through this tour that I became more involved in studying Bermuda’s defences, including researching Bermuda’s American Second World War and cold-war installations in the National Archives in Washington DC.”

Over the next ten years, Mr McGovern visited the island several times to assist Mr Harris in researching Bermuda’s fortifications and helped in the development of the National Museum of Bermuda.

Mr McGovern said: “I believed that a short, economical book on Bermuda’s defences would be of value and help raise local interest in the preservation and interpretation of these historical sites.

“I was able to convince Edward Harris to assist me in creating this book and, more importantly, convince the publishers, Osprey, to agree to add this title to the fortress series.

“I hope that both Bermudians and tourists can use this book to explore these unique defences that provided the primary economic wellbeing for the island from the 1790s to the 1990s.

“By learning and visiting these sites, I believe that Bermudians will embrace the 200 years of their military heritage.”

Mr McGovern will also visit some island fortifications to confirm what defences were built and where, compare with records in the archives and check the physical conditions of the structures.

The lecture at the Bermuda Underwater Exploration Institute starts at 7.30pm and costs $20 for members, $25 for non-members and $10 for students.