River secrets
The river gives us access to its contents, which shift and change as the water ebbs and flows, to reveal the story of a city, its people and their relationship with a natural force
Thames mudlark, Lara Maiklem, is as intent as any yachtsman on tide times and ranges – except where sailors usually want more water, she wants less...
It amazes me how many people don’t realise the river in central London is tidal. I hear them comment on it as they pause at the river wall above me while I am mudlarking below. Even friends who have lived in the city for years are oblivious to the high and low tides that chase each other round the clock, inching forwards every twenty-four hours, one tide gradually creeping through the day while the other takes the night shift. They have no idea that the height between high and low water at London Bridge varies between fifteen to twenty-two feet or that it takes six hours for the water to come up river and six and a half for it to flow back out to sea.
I am obsessed with the incessant rise and fall of the water. For years my spare time has been controlled by the river’s ebb and flow, and the consequent covering and uncovering of the foreshore. I know where the river allows me access early and where I can stay for the longest time before I am gently, but firmly, shooed away. I have learned to read the water and catch it as it turns, to recognise the almost imperceptible moment when it stops flowing seawards and the currents churn together briefly as the balance tips and the river is once more pulled inland, the anticipation of the receding water replaced by a sense of loss, like saying goodbye to an old friend after a long-awaited visit.
Tide tables commit the river’s movements to paper, predict its future and record its past. I use these complex lines of numbers, dates, times and water heights to fill my diary, temptations to weave my life around, but it is the river that decides when I can search it, and tides have no respect for sleep or commitments. I have carefully arranged meetings and appointments according to the tides, and conspired to meet friends near the river so that I can steal down to the foreshore before the water comes in and after it’s flowed out. I’ve kept people waiting, bringing a trail of mud and apologies in my wake; missed the start of many films and even left some early to catch the last few inches of foreshore. I have lied, cajoled and manipulated to get time by the river. It comes knocking at all hours and I obey, forcing myself out of a warm bed, pulling on layers of clothes and padding quietly down the stairs, trying not to wake the sleeping house.
When I first started looking at tide tables, they confused me. I’m not a natural mathematician and numbers just bewilder me, so a page filled with lines and columns of them sent me into a flat spin. But I’ve been studying them so long now that they’ve become second nature. A quick glance and I can see which tides are good and when it’s worth visiting the river. The most important thing is to choose the correct tide table for the stretch you are planning to visit. There can be a difference of around five hours between low tide at Richmond and low tide at Southend, since the tide falls earlier in the Estuary than it does at the tidal head. Even the length of the low tide varies depending on where you are. While the rise and fall of tides in the open sea are of almost equal durations, twenty five bends in the tidal Thames and the
dragging effect of the river bed and its banks shorten the river’s flood tide and lengthen its ebb tide. This means that the river stays at low tide for longer at Hammersmith than it does in the Estuary, which in theory equates to more mudlarking time the higher up the river you go, but even then, depending on the weather and the slope of the foreshore, the river can still catch you out.
I never look at the high-water levels, but I know that a good low tide of 0.5 metres and below will expose a decent amount of foraging space, so I scan the tide tables for these and circle them with a red pen. Spring tides mark the highest and lowest tides of the month. The name comes from the idea of the tide ‘springing forth’ and not, as some mistakenly think, the time of year when they occur. There are two spring tides every month, when the earth, sun and moon are in alignment and the gravitational pull on the oceans is greater, but the very best spring tides are after the equinoxes in March and September when they can fall into negative figures. They are known as negative tides because they fall below the zero mark, which is set by the average level of low tide in a specific place. A few years ago there was a run of freak low tides that were lower than most mudlarks can remember. These were the best tides I’ve ever seen. They revealed stretches of the foreshore that hadn’t been mudlarked for over a decade.
It is the tides that make mudlarking in London so unique. For just a few hours each day, the river gives us access to its contents, which shift and change as the water ebbs and flows, to reveal the story of a city, its people and their relationship with a natural force. If the Seine in Paris were tidal it would no doubt provide a similar bounty and satisfy an army of Parisian mudlarks; when the non-tidal Amstel River in Amsterdam was recently drained to make way for a new train line, archaeologists recorded almost 700,000 objects, of just the sort we find in the Thames: buttons that burst off waistcoats long ago, rings that slipped from fingers, buckles that are all that’s left of a shoe – the personal possessions of ordinary people, each small piece a key to another world and a direct link to longforgotten lives. As I have discovered, it is often the tiniest of objects that tell the greatest stories.