I remember once speaking to a nice old guy who worked on the royal yacht Britannia from the day of its launch in Clydebank in 1953 to the day he retired in the 1980s and it seemed to me that his experiences pretty much summed up our difficult, complex, but ultimately valuable relationship with the royal family.

The old guy’s name was Ellis Norrell and some of what he told me made me uncomfortable and some of it was quite moving. For a lot of his time on the yacht, he said, he and most of the crew slept on hammocks, all his belongings in a tiny cupboard, and whenever he saw the Queen he had to bow his head and say “ma’am”. Where you ate and drank was also divided by rank.

Pretty much all of that – them and us, the bowing of the head – didn't sit well with me, but Mr Norrell also told me how the ship, for him, became a kind of constant: he’d just lost his wife, he said, and Britannia became a kind of second love. He also told me how all the clocks were stopped at one minute past three to mark the time the Queen stepped off the vessel for the last time. They’re still at one minute past three now and will be forever, I guess.

The fact that Mr Norrell’s experiences send out different signals is, I think, just as it should be during this platinum jubilee. It’s ludicrous that people should bow their heads and say ‘ma’am’. It’s troubling that some people can’t pay for their heating while other people ride around in golden carriages. And it’s right to question the cost of it all. John Lydon of Sex Pistol fame said the other day that he has no animosity towards the royal family but objects to the assumption he should pay for it. “No,” he says, “you’re not getting ski holidays on my tax.”

I understand all of that, and it makes the argument for a much-reduced royalty. But Mr Norrell’s experiences on Britannia, and the fact it was a constant in his life, touches on something else that’s important. The Queen’s reign has been one of total change and some of it has been splendid (the sexual revolution, new technologies) and some of it has been disturbing (Brexit, cost of living) but the Queen herself is one of the few continuities: she was there in the ‘50s and she’s still here now, unchanging.

Or: almost unchanging. Britannia is gone. Much of the head-bowing deference is gone. And even the way the Queen speaks has changed as Britain has become more informal. In other words, the institution has been tweaked and adjusted to match the times while also offering a point of constancy, a through-line from then to now, from how-we-used-to-be to how-we-are. For Mr Norrell, it was Britannia. For us, it’s the Queen.

I appreciate not everyone feels this way and some people have no need of queens and golden carriages as symbols of the constant. But as the historian Tom Devine put it to me recently, when we look at the panorama of the past, there’s been a structural transformation in virtually every aspect of society and it seems to me that when the change is so profound, we need something unchanging; in choppy waters, we need some dry land.

For royalists like me – for that is what I am – the monarchy is one of those things that’s provided the patch of land, particularly in the last ten years when the pace of change and chaos has if anything accelerated: austerity, referendums, war, cost of living, Twitter, the “culture wars”. Through all of it, reminders of continuity are important. More than that: they are vital.

There are other arguments in favour of royalty and I know you'll be familiar with them. They raise more than they cost (an effect I saw for myself where I live when Prince Charles bought Dumfries House). You also have to consider the alternatives. Boris Johnson. Nicola Sturgeon. Thankyou, but no. Ultimately though, it’s about having something that keeps still in the middle of the spin. The royal family is a totem that's wrapped in velvet and gold. But it’s also a touchstone, or a handrail, or – like Britannia was for Mr Norrell – just a point on the map we can return to when we’re lost.

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