The sight of Donald Campbell’s speedboat Bluebird K7 powering along the surface of Loch Fad off the Isle of Bute last week – albeit at a mere 150mph, or half of the speed at which it was designed to travel – evoked a time when those who broke speed records could claim a degree of fame matching that of a world heavyweight boxing champion. Henry Segrave, George Eyston, JG Parry Thomas, John Cobb and Malcolm Campbell, Donald’s father, were household names in the middle of the last century, fulfilling a mission not only to compete against each other but to prove the supremacy of British technology. And, quite often, to die as a result.

The risk involved in attempting such feats on land and water was part of the appeal to the public imagination. It belonged to a culture that embraced adventurers who competed with each other to plant flags on the North and South Poles, to fly over the Himalayas or to stand on the summit of Everest.

Parry Thomas, a Welsh car designer, was the first man to die in pursuit of the land speed record when his giant aero-engined car turned over while travelling at more than 100mph on Pendine Sands in Carmarthenshire in 1927. The driver was laid to rest in a churchyard near Brooklands, where he had won many races, while the car was buried in the Pendine dunes, from which it was disinterred several decades later.

In the same month as Parry Thomas’s accident Segrave captured the land speed record. When he was killed on Windermere three years later, when his boat Miss England II capsized while he was trying to break the 100mph mark on water, the manner of his death seemed heroic. It was a natural fit with a résumé that included wounds suffered as a fighter pilot on the western front, a victory in his Sunbeam in the 1923 French Grand Prix (the first for a British car and driver), becoming the first man to travel on land at 200mph at Daytona Beach in 1927 and engaging in a fierce and prolonged patriotic battle against an American rival for the record on water. He had been knighted only a few months before his fatal run.

Cobb, too, died on water, on Loch Ness in 1952, when his jet-powered boat Crusader broke up while he was trying to exceed 200mph. At the time he was the holder of the land speed record, set at 394mph on Bonneville Salt Flats in his teardrop-shaped Railton Special, powered by twin aeroplane engines.

His machines, like Segrave’s Miss England II and Eyston’s Thunderbolt, were things of beauty, shaped not by the unsentimental logic of the computer but by the human eye engaged in the task of creating an object capable of moving as smoothly as possible through air or water. The designer’s instinct was to believe that, if the result looked good, then it would probably work.

Attitudes to risk and speed have changed as much as the understanding of aerodynamics. But still, somewhere in the (generally English-speaking) world, someone or other is usually working on a scheme to obliterate marks that are now fast receding into history. To do so in 2018 they would have to beat the land record of 760mph set by the RAF fighter pilot Andy Green in the jet-powered Thrust SSC at Black Rock Desert in Nevada in 1997, or the record for boats notched up by Ken Warby of Australia, who travelled at 317mph on a New South Wales reservoir in 1978. But what would be the point?

For the pioneers the ambition was obvious. Record-breaking drove development and benefited sponsors. The first land speed records were set in the 1890s by French-built electric cars. When the internal combustion engine offered greater performance, the newer technology took over. More speed translated easily to the market, although those aims were becoming blurred by the time Donald Campbell walked into the spotlight in the 1950s. Passenger cars and boats had long since exceeded the sort of maximum speeds any normal person would sensibly require.

But Donald Campbell was competing against more than records and rivals. He was competing against the memory of his dead father. Sir Malcolm Campbell had fought at the Battle of Mons, won grands prix in Bugattis and, at Bonneville in 1935, became the first person to drive at 300mph. Despite his public support for Oswald Mosley’s British Union of Fascists – the Blackshirts – in the 1930s, he spent the second world war in charge of the plans to evacuate King George VI and his family in the event of a German invasion. He died in his bed in 1948, aged 63.

He was demanding and even ruthless, and his son could not escape his shadow. “He was the most important single influence on my life,” Donald Campbell told the writer John Pearson in 1964, during a fraught trip to Australia, during which he eventually topped 400mph to set a land speed record. “You could come up with some very fancy Freudian theories to explain what I’m up to here.” Three years later he was killed when his boat reared up on Coniston Water and crashed on its back at around 300mph.

In 2000, when divers located the broken K7, with his body still in the cockpit, his family was divided. Some, including his widow, thought the retrieval project was a bad idea. His daughter, who had made record attempts of her own, was all for it. For the rest of us the reappearance of that distinctive humpback hydroplane provides a reminder of a time when heroism was seldom questioned and progress in technology was assumed to be benign.