Simon and I set off in opposite directions. Simon was making his way back to his car near Aldeburgh, and knowing his luck he would find a new, traffic-free shortcut that would cut his journey in half. Meanwhile, I decided to head for Shoeburyness, on the edge of Southend-on-Sea, to have another shot at seeing the pair of modern lights near Maplin Sands.

By lunchtime, I regretted that decision. First, because the lights themselves were entirely unremarkable. I managed to get an adequate long-lens shot of one of them, a green-painted steel lattice tower, but the only other structure close to it was a green lit buoy. Second, because by coming here I had probably added forty miles to my journey, and had almost nothing to show for it.

The Maplin Sands Lighthouse is long gone, but there are still a few buoys and beacons offshore #beaconbike pic.twitter.com/PzeofCSb0t

— Edward Peppitt (@thebeaconbike) August 3, 2015

The original lighthouse at Maplin Sands was a famous one, having been the world’s first screw-pile lighthouse. The sharp-eyed readers among you will remember that this was a claim also made of the Wyre Light, off the coast at Fleetwood. The truth is a little complicated. The Maplin structure’s screw piles were the first in place, although the Wyre Light was the first to display a light. Either way, it’s an academic argument, since the Maplin light was swept away by the sea in 1932.

There were once a number of other lights along the Thames Estuary, at Chapman Sands, Mucking and Purfleet, but all have long since been demolished. These days, vessels out in the estuary navigate with the assistance of a series of lit markers and buoys.

There are, however, a number of lights of interest further along the River Thames itself, so I planned out a route that would take me along the north bank of the river as far as Trinity Buoy Wharf, near Blackwall, then cross the river using the Woolwich Ferry to follow the south bank all the way to the north Kent coast.

The only part of the plan I didn’t like was the first twenty miles out of Southend-on-Sea. Whichever cycling app or route planning service I consulted, the only feasible route seemed to be straight along the main A13 road into London. For the first mile or so, while still technically in Southend, I could retreat to relative safety on broad pavements. But as soon as I was outside the town, the road became a dual carriageway at regular intervals and the traffic speed doubled as a result. Without doubt, these were the most frightening ten miles of the 3,200 I had cycled since May, and at one point I found myself on the inside lane as another dual carriageway merged into mine. All four lanes were full of fast-moving traffic, and I was suddenly right in the middle of them.

Beyond Tilbury, I left the A13, found a hotel, and drank two large glasses of Cognac to calm my nerves.