We left Hampton Court knowing that there were only a few miles and one lock before the Thames, now almost at its mouth, no longer meanders comfortably downstream, but instead ebbs and flows with the estuary it is about to join.

When in a rash moment down the pub I had first proposed doing this journey there was a good deal of head shaking and teeth sucking:  That’s tidal, you know, everyone warned.  My blog readers might suspect I wear my captain’s hat with irony.  My fellow drinkers were quite sure I was out of my mind.

So today, what with the boaty adventures ahead and making phone calls every half hour to get any updates on my younger daughter (safe but not talking to either of her parents; suddenly her boyfriend was my new best friend),  I was a little tense.

We pulled into the lock moorings at Teddington, and Mr Crew and I strolled up to the lock keeper’s office.  I said, I’m on a narrow boat, and we are heading downstream to London.

The lock keeper rolled his eyes.

But only as far as Brentford today, I said, and he cheered up, just a little, before delivering a physics lesson, pretty much repeating what I had already been told: since the tide on the Thames comes in faster than the comfortable speed of most narrow boats, we wouldn’t get very far unless we waited until just before high water.  By the time we locked through, the tide would almost be slack, and then, as we travelled down river it would turn, and we could ride the flow as the Thames rushed past the outer suburbs and hurried towards London.

We had a couple of hours to wait, and then the crew and I donned life jackets for the first time. Mr Crew was eager for us to set off, but because I was just as eager not to commit the faux pas of passing boats moored ahead of us in the lock queue, I got lots of good driving practice, hovering mid river while other captains mustered their crew and pushed off.   There was a general air of excitement as finally the lock keeper signalled it was time.

When the downstream gates of Teddington Lock opened and we spilled out, I felt as if we had crossed into some new, dangerous territory.  As I had got closer and closer to this five mile journey, everyone had confirmed my unease by being impressed with the very idea:  That’s tidal, you know.

But all was well.  We flowed the four and a half miles with the ebbing river, past Twickenham on the left, and Richmond on the right and on by Kew Observatory.  Just beyond the Royal Botanic Gardens at Kew, I turned the boat sharply to the left.   In the late afternoon sunshine we went through Thames Locks and left the river.  The crew, Pangolin and I were on new water:  the Grand Union Canal.

Day 9 statistics: 5 miles of large rivers, 5 miles of tidal rivers, 2 large locks and 1 broad lock.

Waiting for Teddington Lock

The tidal Thames looked a lot like the non-tidal Thames, really.

Ham House (17th century)

Richmond on Thames

Richmond Lock is only needed at low tide.

Leaving the Thames

I worked Brentford Gauging Locks (hard work pushing those buttons) while Mr Crew drove. It was the last lock of the day, and the first on the Grand Union.

And here’s a map, so you can see where we are.  The yellow highlight is the route we have already taken.  The orange highlight is what is coming next.  (As with the other pictures you can click for a better view; I’ve made the map one quite big…)

The trip so far: Baker’s Lock to Brentford Gauging Lock, via Oxford: 108 miles and 41 locks