The talk that Rear Admiral Bob Mark gave to Kingswear Historians attracted a wide audience: historians, scientists, sailors and people who just wanted to know more about navigation.

The title, “Trust in God and an Admiralty Chart”, traced the development of hydrographic equipment from 1680’s to the present day.

Bob showed pictures of early sailors taking soundings from a sailing ship using plumb lines with depth markers. Surprisingly this worked so well that that it was still being used 300 years later.

The science of finding out where you were on a vast, empty, ocean was somewhat more complex.

It required knowledge of trigonometry and understanding of astral science.

More importantly, it also required some agreement between different countries about what navigation markers to use.

For a long time, France and Britain disagreed about whose system to use until the Greenwich Meridian won out and it was agreed at an international conference held in 1884 that the line that passes through the Royal Observatory at Greenwich, would become the international standard prime meridian used world-wide for time keeping and navigation.

Luckily there was more co-operation when it came to charting waters.

Mariners from different countries shared their knowledge of reefs, depths and shifting sands, thus helping to keep other sailors safe from shipwreck disaster and adding to the success of expeditions to the other side of the world.

While many of our land based scientists became household names, hydrographers are far less well known, their names tending to appear as remote headlands and deep areas of the ocean. An exception, the hydrographer, Francis Beaufort, who served in the Royal Navy gave his name to the Beaufort Wind Scale, used by sailors and land lubbers, and which he devised in 1805.

The audience were fascinated to hear that in modern sea conflicts, false readings and deceptive signals are often used as weapons of war to lead the enemy into danger.

At the end of the talk, audience member, Lisa Brown, commented, on Bob’s career as a hydrographer, “It took him to some amazing places and after the talk, I felt I knew a lot more about the history of navigation .”

Bob Mark lives in Kingswear and enjoyed a 32 year career as a seaman officer in the Royal Navy.

Early on, he was fortunate to occupy an office in the Master Rope-maker’s House in South Yard, Devonport built in 1773.

Jonathan Turner will be giving the next talk for the Historians.

“Taken by the Turkes” which will cover captivity, ransom and conversion among Dartmouth Seafarers in the 17th century.

Jonathan has a strong interest in local history, is the Chair of the SW Marine History society.

He is also a member of Dartmouth History Research group and a Trustee of the Museum.

It will be held in Kingswear Village Hall on Monday December 8 at 7.30pm, entry £5 and all welcome.

For more information or to get in touch you can visit: https://kingswearhistorians.com/ or e-mail:[email protected]