A while back, I wrote a post about the “GPS Bubble,” which led me to discover that a woman, Mary Blewitt (later “Pera”), had written the standard text on the subject of Celestial Navigation, way back in 1950. Blewitt’s book, Celestial Navigation for Yachtsmen, is a true classic, now in its 12th edition. As you can imagine, I was curious to learn more.

A Google search landed me on the nautical publishing section of Bloomsbury Publishing, where I found this: “The late Mary Blewitt, better known by her married name of Mary Pera, was involved with sailing for most of her life. Formerly a top ocean racing navigator as well as secretary of the Royal Ocean Racing Club for a number of years, she was also Chairman of the ISAF racing rules committee, and an international judge and jury chairman at major championships and regattas.” On that same page, Sailing Magazine recognized Celestial Navigation for Yachtsmen as: “The ‘bible’ of navigation for generations of yachtsmen… worth its weight in gold.” And further, World Cruising had this to say: “Celestial Navigation for Yachtmen is a model of simplicity and clarity.” Who was this lady who had written this indispensable volume?

Yet another Google search landed me on the UK’s Daily Telegraph, where, sadly, I read Mary Pera’s 2002 obituary.

“MARY PERA, who has died aged 77, was an outstandingly skilled navigator of ocean-going racing yachts.

Her experience helped to make her Celestial Navigation for Yachtsmen the definitive guide of its time to navigating by the stars. It was first published in 1950 and appeared in 10 revised editions during the next 30 years. She had the knack of demystifying the subject for sailors all over the world.

Mary Pera’s interest in navigation first found expression after the Second World War. Realising that the cramped environment of a small boat was more akin to the cockpit of an aeroplane than the chartroom of a large warship, she began publishing articles based on techniques developed by the RAF during the war. From these developed Celestial Navigation for Yachtsmen, which remained a standard text until the late 1980s, when navigating by the heavenly bodies was overtaken by satellite technology.

Mary Pera proved that it was possible for a woman to take a senior position on a racing yacht – although she encountered some resistance. ‘There were a lot of Navy people who were particularly tiresome,’ she recalled. ‘They gave themselves airs, as if they were the only ones who could navigate. But it wasn’t that difficult.’

She was born Mary Blewitt at Boxted Hall, the family home near Colchester, Essex, on July 20 1922. Her father, Colonel Ralph Blewitt, was a notable offshore sailor and team manager of the Royal Yachting Association’s Olympic team in 1948.

Mary grew up on the East Anglian coast and as a child sailed dinghies from West Mersea, later racing in Burnham Week and cruising and racing at Cowes. Having lied about her age she joined the WAAF at 17 and served as an intelligence officer during the war.

In 1946, she completed the Hook Race, to Holland. She became a member of the Royal Ocean Racing Club and despite regularly racing offshore she still found time in 1948 to be called to the Bar.

Myth of Malham, winner, 1949 Fastnet Race

Myth of Malham, winner of the 1949 Fastnet Race

In the late 1940s and early 1950s, Mary Blewitt was navigator on some of the most celebrated and successful racing yachts in competition. In the Fastnet Race of 1949 she was a member of the crew of Myth of Malham, perhaps the most famous British racing yacht of the 20th century.

Myth of Malham belonged to Captain John Illingworth, founder of the Sydney-Hobart Race, and Peter Green, later chairman of Lloyd’s of London. Illingworth was primarily responsible for launching offshore racing in both Britain and Australia. These two men were in 1957 among the five donors of the Admiral’s Cup, the most influential international ocean racing series.

That year Mary Blewitt married Captain G B Pera, an Italian naval officer whom she had met when she was navigator of Myth of Malham. The couple settled in Rome, and Mary Pera spent much of the next decade racing in the Mediterranean.

In 1969, only a few weeks after the early death of her husband, Mary Pera was the driving force behind the entry of the Italian team to the Admiral’s Cup, the first Italian challenge for the race. She organised the transport overland of the team’s three boats, which included her husband’s yacht La Meloria.

By this time Mary Pera herself had been forced by rheumatoid arthritis to stop sailing. Yet the condition never affected her drive or determination. In 1972, in succession to Alan Paul (“The Apostle”), she was appointed Secretary of the Royal Ocean Racing Club.

Mary Pera remained Secretary of the RORC until 1978. In that year she published Racing Rules for Sailors. In the latest edition, following the complete overhaul of the rules of yacht racing, she explained the changes and provided a practical commentary on the application of the new rules.

She had become a member of the RYA Racing Rules Committee in 1977, and soon afterwards became its chairman, which she remained for the next 20 years. From 1982, Mary Pera was a member of the Racing Rules Committee of the International Sailing Federation, the sport’s world governing body, where her gift for elucidating complicated issues proved invaluable.

Her other books included Surveys of the Seas (1957), a study of historical charts in the keeping of the Hydrographic Department of the Admiralty. During the 1950s she was assistant editor of the Journal of the Royal Institute of Navigation, a body of which she was made an honorary member in 1996.

She always maintained that yacht racing should be fun, and she made it so. Highly self-reliant, Mary Pera had a penetrating mind and a gift for making clear decisions.”

I’ve just recently received her book in the mail, and plan to read it from cover to cover, but in closing, I wanted to quote a bit from the author, taken from the preface, dated 1994: “Today, yachts race across the oceans using GPS and other navigational aids with no sextant on board. And this is fine, provided of course — and it is a very important proviso — that the instruments function correctly and the batteries stay in a condition to operate the electronic equipment. Ocean voyaging is obviously safer with the new instruments, but just as a driver needs contingency plans for a flat tyre, so a navigator needs a fall-back when sophisticated instruments fail. Offshore, that fall-back must be astro.”  Wise words, indeed: as I had written in an earlier post, the U.S. Navy has just recently begun teaching celestial navigation again – for just that reason – so that their sailors can still navigate should GPS and other navigational instruments fail.

What an amazing person Mary Blewitt Pera must have been. Her unquestionable competence enabled her to clear the highest hurdles in sailboat racing, navigating ships in the most demanding of offshore races. Let’s not forget her history, her accomplishments, and her incredible contributions to the sport of sailing. But perhaps her most enduring legacy is her book, written nearly 70 years ago, and which is now considered a “standard work,” a clear, concise guide for navigators — still highly relevant, and greatly respected today.

How’s that for staying power?


Deborah Bennett Elfers
I was practically born on a boat, though on a working lobster boat rather than a sailboat. In my early days, I sailed quite a lot on a Sunfish, but not very elegantly, as in our little neighborhood “fleet,” the boat was primarily used as a weapon in a wildly popular game of “kill the other guy!” Who could have imagined way back then, that one day I’d become so passionate about all things sailing?
Deborah Bennett Elfers
Deborah Bennett Elfers

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