Until 1992 the Port of London Authority maintained a gauge at this fort to measure the state of the tide in the Thames Estuary. As sea levels rise and the south east tilts slowly into the sea, these observations assume even greater importance. Newer technology on a nearby buoy now relays this information more efficiently. A bank of batteries, a generator, oil tanks, diesel and other smaller clues remain, as to how it was all done before.

Exploration of the Fort's second Wash House, commandeered by the PLA is now complete. A few traces remain of its earlier function; a fragment of urinal or the brackets that held the cistern for example, but they are now all coated with later oily residues.

A card in a PLO envelope, has a message for Keith Millen about 'O' rings needed for a faulty valve. 'Nancy Sinatra wrote that These Boots Were Made for Walking...' begins a hand written note, which if topical dates it to 1966. My own boots nearly walked over it, as I pulled shut the door.

Boats occasionally pause outside with people who want to see the recluse and I will sometimes give a friendly wave from a window. St Anthony the Abbot would have liked being here. He lived alone in an abandoned fort for twenty years and though he barricaded the place for his solitary contemplation, people repeatedly broke in to see him. Shivering Sands is essentially proof against all but spiritual visitation.

The rag of the fish patterned shirt was fittingly found beside the top of the ladder. Many discarded remnants of fabric were used to clean the machinery or the operatives. A collarless shirt is replete with greasy handprint. Half a mini skirt was under an oil can. The tie dyed "Growing Girl" summer dress, rotted on a ledge behind an acetylene cylinder. When were they made? Where were they worn? Who brought them here? Re-used remnants of different lives and times, now made part of mine.

Rusty precipitation falls on the tent every night with a slow but regular patter. All my equipment would be covered in a film of new deposits if I did not regularly dust it down. Every day I ritually sweep around the tent, an act akin to maintaining a clearing in a wood. When people leave, or stop caring, nature soon takes over again.

I finally ventured into the engine room, the heart of the fort system. Its four Gardner diesels once provided power for all seven towers in the cluster; their guns, searchlights, radar, as well as hoists, refrigeration, domestic power and navigation lights.

Carefully tended generator sets of once lustrous grey metal, have turned to rust. Bearings, casings, radiators and fans are melding into single homogenous forms through exposure to the moist sea air. It is a world of iron oxide now.

On leaving, I encountered a ferrus planet transiting the steel screen beside the door. It seemed to be in thrall to a band of sunlight entering via a hole in the outer wall.

Shadows creep along the walls of the Fort as the sun dips surely toward the horizon. I wonder what traces of my own brief journey here, will lodge in the flaking and peeling, patina of place?

I discovered Cassiopeia in the boiler room today, rising over the firmament of a barren floor peppered with small illuminated holes leading to the void below. On closer inspection I saw through my error, and realised I was looking onto a series of five green and watery planets.

Worsening weather forecast for the weekend made it essential to leave the fort today and I was collected by the Lady Irene at 6pm, two days earlier than planned. I am truly grubby. The flies that had taken to hovering about my head will really miss me.

I have been crawling about on hands and knees in the dirtiest parts of the Fort and I'm looking forward to a bath in fresh hot water; with a real sense of gratefulness that I live in a country were I can just turn on a tap. Everything is strange; cars, electric light, conversation, studio and home. In my mind's eye the fort is clear and steady. I feel many different emotions, but right now a great sense of loss.

If you would like to share a conversation with me about the experience, please go back to the web site and check for details of the online discussion forum.