Four households share one steel narrowboat on London's canals, and this log is where one of us writes down what the water taught us on each trip, so that the next crew does not have to learn it twice.

Slow Lock Boating is the logbook of a fifty-seven-foot narrowboat owned in shares by four households who could not each afford, or each justify, a boat of their own. We bought into her in the spring of 2021, when the previous group broke up, and she has lived on a mooring up the Lee ever since. Each household gets a rota of weekends and one longer week in summer. Between turns the boat sits and waits, and the log in the table drawer is how the crews talk to each other.

I am the one who types the log up. The paper version is full of abbreviations, coffee rings and the occasional argument conducted in the margin about who left the water tank empty. What goes on this site is the tidied version: what we did, what went wrong and what we would do differently. It is written for the other three households first and for anyone else second, which is why it sometimes explains things that experienced boaters will find obvious.

None of us grew up on boats. We learned from the towpath, from the patience of people working the locks beside us, from advice shouted across a pound, and from our own mistakes. Nothing here is official guidance, and the rules of the navigation change more often than this log does. Where a figure is given, it is ours: our tank, our stove, our boat's depth in the water. Read the current notices before you set off, and treat what follows as one crew's experience rather than a manual.