There’s a big fish called Ewan that lives underneath our boat in the Walthamstow Marshes.  I can tell he’s there because every so often, when the boat rocks, he lets out a little burp which travels like a water pearl along the hull of the boat and “blips” as it bursts into the air.

The marshes are full of sounds: squishing, slurping, burping sounds; the sounds orchestrated by all the imaginative combinations of mud, rain and river water. There’s Ewan (that Gideon in his more paranoid moments thinks might be a hole in the boat), and then there are the slurping and sloshing sounds that people make outside as they slip on the mud of the towpath by the thorny raised bank. Sometimes you hear the odd splash when an over-eager dog careers into a puddle beside Marion, a green boat next to ours. The puddle is as deep as your ankle. I tried to solve the problem once by placing a bit of plywood into the watery hole, hoping that it would perform the role of a makeshift bridge. But it just sank pitifully to the bottom of the miniature lake, covered with dirty rainwater and stray bits of grass. I hauled it out and chucked it onto another, slightly less water-logged puddle.

It is not uncommon for me to return to the boat in the early evening, to find a jubilant Behemoth prancing through the long grass in happiness at my return. Often I just need to call her name and she emerges from the scrubland like a tiny, safari leopard, sprinting and leaping. This particular evening, I humoured her, chasing her around the boat and up the mound. It was then that I noticed that a number of large dynamic swarms of midges had decided to meet together by the port-side of our boat, in an ill-fated witches coven. They were bumping into each other and knocking heads, popping, fizzing and effervescing with useless energy.

It suddenly dawned on me, almost newly, that we were living in a marsh beside a river swollen with rainwater. The slippery mud and the buzz and hum of flies; the deceptive and deadly glitter of the uppermost river currents, the boggy plank, sucked like a plug into the slippery bank, those circling whirligigs of midges – all made me feel a little nauseous.

The noisy indent my boots make after I alight the mud and hop onto the boat and the new ‘no shoes’ policy onboard, also feel like signs heralding a change of tempo in the daily rhythms of boat life. And the new element of mud has been added to that of water – as one of the most presiding mediums and textures of my life. I live in that slippery, viscose, saturated place – a place I have in common with the walkers in Port Meadow in Oxford, or the dwellers on England’s flood plains or the inhabitants of that vast mathematical salt plain that I visited in Bolivia. It is most definitely wellington boots territory. Every time I make the precarious passage down the side of the muddy bank to the boat, I watch my footing like a falcon. One wrong or badly judged step and I would be down on the mound on my bottom, or straight into the water below.

Now I feel not only like a boater – a liminal traveller on the waterways and canals of London –  but also a martian – I mean somebody who lives on a marsh, and it makes me smile because it reminds me of the BBC adaptation of The Silver Chair in the Narnia series and the fantastic visual vernacular of that film: the marsh folk, the moss huts, the woodland creatures, the men with green hair and gruff voices. C.S. Lewis’s conception of the boggy swamplands stuck vividly in my mind as a child because it meant more to him than just a geographical feature; marsh-land was a whole kingdom of people with distinctive habits and mannerisms.

It seems oddly pertinent now, this illustration of marsh culture as a demented place where odd people live. It is true. Marsh life is one of the strangest lives of all; people make do in a primeval, anarchic way. Marsh-boats are patched together with stray bits of timber and plastic; their weatherboarding is paltry, ad-hoc and cobbled together through serendipity. But somehow I admire these alien vessels, strange and desperate, that grow up on the margin of the Walthamstow riverbank like pores. They are statements of creativity, freedom and yes, iron endurance. They seem to defy the rising house prices and the entrammels of bourgeois domestication springing up all around them in monied Hackney and Stoke Newington. Mesolithic, atavistic, they seem to whisper: In London you can still live as you want. In London you can still be free. In my opinion, marsh boats are the best of all.

The marshes are littered with the bric-a-brack of marsh life just like the flotsam and jetsam that is washed up with the surf on beaches. Strange objects and treasures are disgorged by the mile-deep mud every day. One thing that has particularly caught my attention in this urban tangle is a tarnished fork of metal shaped like a shepherds crook, just outside my window. The shepherd’s crook is at the bottom of the mound, in the heart of the water-logged path. Its unexpected protuberances, echoes that of the spiked briars and brambles on the mound, with their thin, ugly red tendrils. I hacked away at these petulant arms one morning with a pair of scissors as I was doing some path-clearing.

My feeling for the place seems to be epitomised by this metal wand, the rusted trident of the swamp-land-King, or so it seems, thrusting through the boggy soil. Like the spear of Eliot’s malevolent fish-king it shakes menacingly in the wind.