It was an unusual welcome to London. Gazing ahead as we entered the Thames estuary, I made out the dorsal fin of a porpoise, gently rolling through silver waves. Quite a contrast from my first arrival, 10 years earlier, as an impressionable 19-year-old, deposited off the Glasgow bus to the thrilling, screaming capital at night. This time, I had come on my boat, the 47ft wooden motorsailer that had been home to my partner Phil and me for a couple of years. It was our first voyage on her, and though neither of us had a clue what we were doing (we were relying on an experienced friend), it felt good. Boats are meant to move. We hadn’t come far – out of Brighton marina, left along the coast, past Dover and the eerie spectre of the 100 rotating blades of Kent’s offshore windfarm. North Foreland, sleepily familiar from the Shipping Forecast, made real. Then up, into the mercurial mouth of the Thames, that timeless route followed by Julius Caesar in 54BC, Sir Francis Drake in 1580 and ... er, David Beckham in the 2012 Olympics.

I had no sailing background. I had left my home town of Dumbarton, on Scotland’s west coast, for London, traded London for Brighton, university, a career in the arts, considered buying property but the damp basement flats within financial reach didn’t appeal. I noticed people lived on boats in Brighton marina and was immediately gripped. “It’s a practical decision,” I told my family. “We can save for a deposit on a flat.” But the underlying excitement betrayed a long-term agenda. We got a loan of £10,000, bought a 30ft-boat, moved on to it in winter to test the lifestyle at its worst. It was wonderful. It was also cramped (I realised during one blazing argument that I had no door to slam). The novelty made up for that. I had a childlike sense of wonder. Chores were no longer chores – they were looking after the boat; sweeping teak floors with light streaming through the wooden hatch above was genuinely enjoyable.

Susan on her boat on the Thames. Photograph: Will Hutchinson

A year on, we set a budget of £50,000 to upsize and scoured the country viewing overpriced boats in terrible condition. I was taken with Paranormal, a steel motorboat in Rochester that the owner, gesturing to a bent spoon framed on the wall, said had previously belonged to Uri Geller. We spent around £500 lifting her out of the water and appointing a surveyor ... only to discover she was bent. It was a while before I could laugh. Shortly afterwards, my dad phoned with news of a beautiful boat, Pamela Jeanne, in the river in Dumbarton, at almost half our budget. I waited as the painfully slow dial-up connection revealed the pictures line by blurry line: a 1932 gentleman’s ketch. So elegant. She had two masts. My desire to own her was immediate and overwhelming. Before long, PJ was on a lorry headed for Brighton (cost: around £2,000) and I was beside myself with excitement. A couple of years later, I had retrained as a journalist, got a job in London and realised we could move, home and all, to the Thames. I had regrets about leaving the ocean, but what I loved most – PJ – was coming, and we could always return. Besides, what an epic journey to plan.

Something extraordinary happens when you arrive in London by boat. The city is changed for ever. The river opens it up. After following its bends and curves from the sea, you realise that it is why London exists – first perched on Ludgate Hill to trade with the world. It’s striking how little has changed; we are all – tankers bound for Dagenham, cruiseships headed for the sights, us moving home and life – at the mercy of the river’s ebb and flow. Thames sailing barges still drift, as in TS Eliot’s The Waste Land, down Greenwich reach, past the Isle of Dogs: “With the turning tide/ Red sails/ Wide/ To leeward, swing on the heavy spar.” This was where we were headed, past the National Maritime museum, and the meridian line, just beyond Deptford, for a mooring in Surrey Quays, one of the docks built at the start of the 17th century. The Thames loops wide around Canary Wharf, black as tar against the night-lit financial skyline. There’s sometimes a scent I remember from the ocean, as the river floods in from the North Sea; a sweetness wrapped up in the salt, like melon. I love the river’s daily transformation – from lead-coloured to brown, now calm, now rushing noisily, its effortless tidal rise of 20-odd feet. It’s hard to believe this virile river streams so gently up at Oxford by grassy banks where cows stand in its course.

Pamela Jeanne is lowered back into the water after maintenance. Photograph: Susan Smillie

We arrived, those 10 years ago, without permission to stay. We had waited more than a year for a leisure mooring – a long-term licence to berth a boat, but without rights to live aboard. It is notoriously difficult to find a residential mooring in London, and each year brings greater numbers competing for fewer spots (giving rise at one end to exploitative landlords renting “slum-style” boat rooms, and, at the other, extortionate prices for private moorings). It meant discreet comings-and-goings for several anxious months, but our risk paid off; eventually we were granted a residential licence, costing £4,000 a year – even with council tax on top, a small price to pay for a riverside spot in zone 2. Electricity and hyperoptic broadband plug in at the pontoon; there is a pump-out service to empty the toilet’s holding tank, a water tap to fill the two large tanks that last a fortnight – you learn not to waste water.

‘The kitchen is as big as some I’ve seen in friends’ city flats.’ Photograph: Andy Hall/Guardian

There were two of us when we came to London. We have split since, and though I wouldn’t necessarily have made this journey by myself, I’m beyond happy. It is hard to capture without cliche. It’s waking to the sounds of moorhens and ducks, or gigantic carp banging on the hull as they jostle; it’s watching cormorants swoop for fish, or glimpsing a shy heron, still as a statue in the shadows. There’s a seal that lives nearby, too: it visits Billingsgate market for salmon and though I’ve never seen it, the possibility is enough to keep me scanning the water. Likewise the pod of porpoise that turned up a couple of years ago. Then there’s the community of people, the wealth of knowledge and skills swapped in one place – engineers, lawyers, doctors, photographers, people inspired by and invested in their environment (such as the plans lodged by an architect, who lives on a tugboat, to build a floating swimming pool in the dock).

Maybe it’s the atmosphere created by visitors on boats arriving from France or Holland, friendly explorers, beaming from their trip, or perhaps it’s being surrounded by like-minded neighbours, but you definitely get the outdoor bug. My kayak floats alongside, for a paddle before work. There’s windsurfing and dinghy sailing on the doorstep – capsizing is much more fun since I discovered the Thames is pretty clean (it’s tested regularly as schoolchildren learn to sail here). There are sandy Thames “beaches” revealed at low tide, where a neighbour walks his collie and kids dig up treasures. Barbecues are ubiquitous on starry summer nights. The best description I can give is that it’s like being on holiday – all the time. I could tell you that it’s no fun when the sun stops shining but I love the sound of the rain pattering on the deck, the boat gently creaking, stock reducing on the stove.

Fitting in a paddle before heading to work in the mornings. Photograph: Thomas Michelou

This all sounds unbearably smug but there are niggles. It’s a hugely fun life, but not one that appeals to everyone. When it comes to meeting people, particularly in the unfamiliar realm of dating, I wonder if it’s potentially limiting. There are perceptions of a bohemian lifestyle; I suspect people imagine a cramped, hardy existence that doesn’t resemble mine – that I’m stooped in the damp and dark, having cold sponge baths in the salty brine. Or that I’m constantly moving, of no fixed abode, like a watery hobo. What would I do if I met someone who hated the water? Or got seasick? That probably wouldn’t work. There are more serious issues, too. I’ve added value to PJ, not least the £12,000 on shiny new engines to enable annual holidays to France I’ve never managed; she’s probably worth twice what I paid for her. But unlike bricks and mortar, she will not appreciate in value beyond that. So this is about an affordably high quality of life now rather than an investment that will grow. And that feeling of space outside? It’s doubly important because room inside is at a premium. PJ is beautiful – all Burmese teak decks, pitch pine and oak, but she’s also pointy in places, slightly low in others, so storage isn’t generous.

Once a vintage junkie, I took a minimalist approach when I moved onboard, ruthlessly ditching all but the most beloved belongings (technology helped; I kept some books but Kindle is key and happily I don’t have a vinyl fetish). It was liberating. PJ already had plenty of character and there was no need (or room) to add much, give or take a few gifts, such as a lovely ship’s clock from my dad. I have a beautiful little aft cabin, with a double bed, plenty of drawers and hanging closet. Up some steps is a wheelhouse, kept empty, just for the luxury of space. Down more steps into a relatively roomy living space, about 12ft wide at its beamiest. Cooking is important – I opened up the separate galley and saloon so my kitchen is as big as some I’ve seen in friends’ city flats. The mini Aga-style stove (designed by Heritage, a great little company in Cornwall) uses marine diesel for cooking and runs the central heating (so, no, to answer an oft-asked question, it’s not cold in the winter). I turned the forepeak room’s two small berths into one really big bath. Not hugely practical, but the hatch above means I get to bathe under the stars and shower under the sun.

Ship’s cat, Mickey. Photograph: Susan Smillie

Compromising on space isn’t such an issue for everyone afloat. Often, liveaboards will be converted barges, relatively flat bottomed for navigating canals and rivers. As the Dutch know, it makes sense – they’re big square spaces that are easy to fit out. Many (particularly in London) have more square footage than a flat. Some have swimming pools on deck. But, the bigger the boat, the more it costs to buy, berth, and of course, maintain. Every three years I ditch my desk job for a couple of weeks’ graft in the boatyard. You can, of course, pay other people to do the work for you – many people do. I help with the sanding, painting and varnishing required for upkeep, mainly because I enjoy learning about the boat, and to keep costs down – paint and other materials come in at £400, lifting it from the water costs around £1,000 (there’s nothing so nerve-racking as watching your home – including your cat – dangle from a crane). But there are maintenance costs with character properties, too – those old Victorian windows can cost a fortune to fix up, I hear.

As house prices and rentals in London continue to rocket, there’s been a huge increase in people turning to boats as an affordable home. If you can’t get a residential mooring, there’s nothing to stop you buying a boat suitable for the canal network (typically narrowboats), getting a licence (up to £1,000 a year) and “continuously cruising” – moving every fortnight. Which is why there’s been an 85% rise in new boaters on the Regent’s Canal in Hackney this year. I cross the Thames daily, cycle up the towpath to work, and have seen it transform. The self-styled “Haggerston Riviera” is fast becoming a floating incarnation of the overpriced street food scene. All the signs are there – ironic graffiti, pop-up supper clubs, skateboarding adults. The air is heavy with the whiff of moustache wax. There are bookshop boats, vinyl record boats, teashop boats, vegan smoothie boats, “healing” massage boats, cinema boats, boat “venues for hire”. This month, a boutique hotel barge launched in Hackney – £300 a night. It’s – for the most part – vibrant and fun, safer than years gone by, and a far better outcome than a previous soulless proposal to concrete over the canal. But the waterway network is congested. There’s additional pressure on each visitor mooring, and queues at water points and pump-out facilities.

Every other day near the lock gates, there are baffled boys in flat caps with ropes hanging from their hands. There are narrowboats, barges, lifeboats; what can only be described as “makeshift” boats, rafted two and three together, their bows jutting at unpleasing angles. There’s not much room to move – but move they must, and as the terms of the licence make clear, it needs to be more than a few pedantic metres, or a letter will arrive banishing them to the outer reaches of Kensal Green (the horror!) Moving your boat in a confined space is scary – particularly under pressure from boat trip operators short of patience with hipsters drinking Punk IPA who don’t know how to get their 60-foot length of steel out of the way.

And property owners are complaining about “linear villages” cluttering the towpath. Councillor Paul Convery criticised boaters who “send their kids to Islington schools claiming they live in the borough”. There’s an unpleasant whiff of snobbery and prejudice, a depressing unkindness that’s often shown by people sharing a space with those paying less. But there’s a point to some of these complaints, too. The canal network was designed for free-flowing traffic, not as a pretty spot for a cheap home. It’s what the Canal and River Trust’s Joe Coggins diplomatically calls “challenging” to manage – they’ve increased the number of volunteers to enforce the rules and promote better understanding between canal users. Coggins is keen to emphasise the importance of research to anyone considering the lifestyle: where to get your gas, wood or coal for heating; how to charge batteries and generators; the technical knowledge required to maintain engines and bilge pumps.

But the romance of boat life has always attracted a disparate crowd, the original hipster artists – musicians, actors, writers. Dave Gilmour’s Hampton houseboat (and the studio where he recorded Momentary Lapse of Reason) was originally built for a music-hall impresario whose proteges included the young Charlie Chaplin (its deck designed to accommodate a 90-piece orchestra). Chelsea Yacht & Boat Company, established in 1935, described as the original “bohemian houseboat village”, has counted Damien Hirst, Nick Cave and Nigel Planer among its residents. Rod Stewart lived afloat in Shoreham on Sea in the 1960s, on what’s referred to as a “beatnik houseboat” (I’m not sure what a beatnik houseboat is, though this might come close, and no word on whether he ever sailed it) and there have been plenty of anecdotes – some of them possibly even true – of the wild times that ensued there. Malcolm Hardee, the infamous comedy promoter, ran a club on the Wibbly Wobbly, his floating pub next to the boat he lived on in my marina until he drowned after his nightly row from one to the other. He was responsible for a long line of famous characters stumbling around the dock (I was bemused by the sight of a topless and dishevelled Keith Allen emerging from the barge next to me one morning). Boats act as a great leveller, bankers and buskers rubbing up against one another – it’s all a bit Savile meets Cannery Row.

‘Something extraordinary happens when you arrive in London by boat.’ Photograph: Will Hutchinson/Guardian

I’m often asked if I’ll ever move back on to land. I can’t see what could rival the lifestyle I have on this boat, in this city. I look east to Greenwich, to the three masts of the Cutty Sark rising gracefully, 150 feet into the London sky. The tea clipper – the sole surviving example and one of the most famous ships in the world – was built in Dumbarton. This beautiful exile is surely the best thing to come out of that place. Closely followed by Pamela Jeanne. There’s a pleasing symmetry in the odd reunion of these two boats so far from home – once sailing the Clyde, now a few hundred metres apart along the Thames. With boats, it’s always about the journey, and while the Cutty Sark is firmly at home in the maritime world heritage centre of Greenwich, Pamela Jeanne still has some ocean trips in her; she’s just waiting on me to untie her ropes.

Susan Smillie is the author of The Last Sea Nomads, Inside the Disappearing World of the Moken – a Guardian Shorts ebook about the tribe who survived the 2004 tsunami.