The 71-year-old Yorkshireman trying to keep this once booming industry afloat

Brian Walker is, ironically, not much of a sailor. 'When I first started my job, I went on a ship to collect some stuff and afterwards it sank. And then, when I went back to fit all the stuff about a year later, it sank again!'

Walker, 71, is one of two people in the UK handmaking nautical compasses. He's employed by B Cooke & Son, a 161-year-old marine-supplies shop based in Hull. B Cooke & Son sells products it has bought from elsewhere (maps, thermometers, globes) and products made or adjusted in-house (clocks, barometers, compasses). Other primary staff include Priyanka Perera, the 61-year-old MD who also works on the shop floor; Norman Cammish, a 70-year-old who makes clocks and barometers; and Sylvester Perera, Priyanka's 30-year-old son who, in 2016, left his job in IT and retrained under Walker to become a compass maker. (Sylvester is also qualified as a compass adjuster – which means he fits compasses on to ships.) I ask Sylvester what it's like to work with no one his own age. He says, 'There's an abundance of knowledge here,' which is a diplomatic answer but, also, true.

Walker joined the company at 15 as an apprentice. 'I already had some skills from school because I liked to strip down engines and stuff like that. I was practically minded, and that's, really, what got me the job.' He was trained by the director of the company ('a chap called Mr Busby') and his first task was sweeping the floors. Then he was taught 'simple machining', then 'cheap metal working', then 'tapping and drilling', then 'spraying, turning, milling, fitting' until, after five years, he had learnt 'all the principles of engineering' and was able to make a compass by himself. It sounds like it would require a lot of patience, but Walker enjoyed the process. Learning everything in stages 'was like a story – you got interested in it'.

There were around 20 other staff members when he began at the firm. Several of them moved to work at a nearby aeroplane manufacturer in Brough, where the wages were better. (In 1968, Walker was earning around £2-£3 a week.) But Walker wanted to stay at B Cooke & Son. 'I liked the work because I was doing a bit of everything.' Also, 'It's a small family company and you're not just a number, like you are in a big firm.'

Walker does not make small compasses that you carry around in your pocket, rather he makes large magnetic compasses to order, which are fitted in ships. Making one of these is a long and complicated process. You need to attach a magnet to a compass float and then screw these two things on to a compass card – the disc that has directions on it – using an industrial sapphire. (Sapphires are resistant to cracking and scratching.) Once attached, the magnet, float and compass card are fixed to an 'iridium tipped pivot' – another needle, that rotates. That structure is then placed inside of, and bobs about in, a brass 'compass bowl' which is itself filled with spirit (industrial alcohol) and sealed with a glass cover. The finished structure goes inside of a 'binnacle' – a large, dome-shaped container made from fibreglass.

The largest versions weigh 12kg and cost £1,200, but they ought to last for ten years, maybe more, depending on the weather. The price accounts for labour (one compass takes about six weeks to finish) and materials (Walker buys all his components from British suppliers, which is not cheap). The cost of brass, he says, has gone up enormously: 'It's like flipping gold.'

In the company's heyday, Walker was making as many as 80 compasses a year, often supplying bulk orders to shipyards. Today he's unsure on the exact number but says it's far fewer. 'Everything is now made to order.' (Alongside compass making he also does repairs on sextants, a marine navigation tool.) I assumed this was because of improvements in sat-nav technology, but that's not correct. Passenger ships – ferries and cruise boats – are still required to have a compass. 'It's a standby. If your sat nav breaks down you need something that won't break down. A compass doesn't need electricity. It works in any weather.'

Instead, the dwindling sales are, partly, the result of accountants. It used to be that ship captains would choose their own compasses, and, as they were actually the people having to use them, they valued quality. 'But then shipyards started relying on accountants to do all the buying [for the ships] – because it was cheaper that way – and instead of looking at quality, [the accountants] went for cheaper versions.' That meant less expensive plastic compasses – even if they were ultimately more prone to leaks – were picked over Walker's brass ones.

It's also because the British shipbuilding industry has, almost entirely, vanished. Walker can remember there once being at least ten shipbuilding firms in Hull alone; now, he says, all of them have closed. And, 'if a ship is built abroad, well, it's kitted out abroad, isn't it?' There's no logical reason for a ferry that's been made in China or Germany to be fitted with a compass that's been made in Britain.

Walker's office is on the fourth floor of B Cooke & Son's building and has a gigantic glass window. Through it you can see Hull Minster – a grand, stony church more than 700 years old – and, in the distance, the River Hull – which will lead into the River Humber, which will lead into the North Sea. When I comment on how pretty it is, Walker says the view used to be better. 'I could see Paull Lighthouse and I could see the river.' In fact, the view was so clear that his colleague Alf – a compass adjuster who fitted Walker's creations on to ships – would be able to wave at him from the boats.

Today, the harbour has no ships in it and the view is obstructed by a combination of solicitor's offices, a Tesco Extra, a block of luxury flats and a 2,104sq ft office unit that is – I notice when I leave – to let.

I ask Walker what he likes specifically about making compasses and he says, again, that it is the satisfaction of the process: the reward in making an entire object from beginning to end. Later, when I ask Sylvester the same question, he says much the same. 'It's quite pleasing to make something start to finish. If you look at that compass there,' he points to a large one, 'every part of it we made by hand. You start from absolutely nothing! Then you see all of these parts slowly becoming a compass. Also, it's therapeutic, doing the work.'

Walker has no intention of retiring soon but, when he does, Sylvester will likely be the only remaining compass maker in the country. He hopes, however, that won't be the case for long.

'I think Brian felt that the knowledge [of compass making] was passed down to him and it was his responsibility to pass it down again.' Sylvester feels the same responsibility. 'Everything he has taught me, I have to teach someone else at some point. So, no, I don't think I'll be the last compass maker.'