We in the affluent West tend to overprotect and underestimate our children. We track them with technology, keep them close, helicopter over even their university lives. Yet the world’s history shows that young teenagers can do great things: support families or lead small siblings across war-torn continents. Sometimes we may look at the helpless creature on the sofa and wonder what we have done.

That, however, is no reason to send a girl of 13 alone around the world in a 26ft boat, battling the courts to do so.

Laura Dekker is plainly competent, a veteran of family journeys, and says that she wants to break a record. Good for her. But good for the Dutch authorities, too, who blew the whistle.

I have sailed often in Dutch company, and they are a seamanlike and sensible people: it is precisely those qualities of realism that are now thwarting this child and her worryingly keen parents.

Her advocates will cite earlier examples — including our own Mike Perham, who docks this week at 17 with the world record under his belt — but when Mike did his first lone voyage, across the Atlantic, he was already a year older than Laura and his father prudently sailed nearby in an identical boat. Even so, a sigh of relief greets his return.

A singlehanded sailor needs more than competence: the loneliness is extreme, the mental challenge intense and the potential for self-doubt and delusion has made grown men such as Donald Crowhurst founder. This girl’s parents may feel that modern navigational aids and communications make the difference, but such stuff can break. Especially in a damp little 26ft boat.

Laura may be fit to fix a broken rig or install a jury rudder — assuming the physical strength — but overhauling a sat-phone or GPS is beyond anyone.

As to her intention to “rest in ports to avoid bad weather”, bad weather strikes suddenly at sea, and to put it bluntly the world is full of ports considerably less benign and civilised than The Hague. Like it or not, a 13-year-old girl alone in a harbour is more vulnerable than a 17-year-old boy.

This piece of vainglorious prize-hunting is a bad, bad idea. Quite apart from anything else, she plans to take two years. That blythe 13-year-old certainty will fade. Ask any woman who remembers her teens and she will tell you how loopy, unsure, even borderline delusional she was at times when she was 14 and 15.

Then imagine those feelings crowding in on a child alone in a pitiless ocean, the wind contrary, the water running low, and no signal to get through to your mum or best friend. No: Laura has a great seafaring life ahead of her. Which is where it belongs.

Ages of consent

13 Have sex in Spain

15 Drive a car in New Zealand

16 Marry in Britain (with parental consent)

16 Vote in Austria and the Isle of Man

16 Join the British Army

18 Buy a rifle in the US

18 Buy cigarettes in Britain

20 Vote in Japan

20 Marry in China, if you are a woman

21 Buy alcohol in the US

22 Marry in China, if you are a man