The roaring acceleration of the Thames Clipper catamaran as it clears Tower Bridge certainly blows away one's irritability. I woke this morning feeling acutely dissatisfied. I concluded it was down to a concern that the holiday weekend was going to slip away wet and cold and otherwise unremarkable.
We'd lasted about thirty minutes in the storms and the sticky mud of yesterday's funfair on the Heath. I mean, I've still got in my coat pocket a token left over from the Bumper Cars (three goes for £6 rather than £2.50 each). Things had got desperate.
Today just had to be better! But without a plan we were drifting to a listless and boring trip to the shops, at best.
The eldest came to the rescue, asking whether we might go on a boat to Australia (the antipodean enthusiasm continues). We both knew how he felt. But no, not Australia - Greenwich, however, might be a possibility. After a look at the TfL website, it was down to St Pauls on the handy number 56, across the wobbly bridge - whose steel-grill floor had a sugar-on-a-silver-salver quality in today's glimpses of sunlight - and we were soon walking the gangplank from pontoon pier to catamaran deck.
You take the couple of stops before the Tower sedately. You're paddling in the Pool of London and not really on the open river. On this stretch, it's mostly office buildings and, the eldest's favourite view of today, HMS Belfast. But once you're out of the Pool you speed eastwards, churning up enough of a wake to lift your spirits - transported.
Now you're sweeping down a shuffled frontage of Victorian warehouses and modern blocks, all of them pretty much given over to flats: mile after mile, there's that many. It brings home how London's business used to be things - from everywhere you'd care to mention they came to these wharves to be loaded, unloaded and reloaded - but now it's people. Most everything along the river now is for people: to live in, to drink in, to eat in.
Our roaring scud paused briefly beneath the citadel of Canary Wharf and then, in no time really, we were in Greenwich. A short walk around the Naval College seemed about right as it still hadn't rained.
I enjoy the melancholy air here. It's like the abandoned, moth-balled capital of a mysteriously disappeared nation. Such grandeur but to so little purpose nowadays. You turn a corner, half expecting to stumble across a royal court still slumbering under some centuries-old malign spell. But today we wondered into an Indian wedding, which was being conducted next to the chapel, the bright silks not looking at all out of place in this baroque setting (touches of Vanity Fair). I almost wish it could be left to sublime and picturesque ruin.
However, dilapidation may have to wait. Despite the downturn, London looks as if it's still compulsively reinventing itself: cranes and scaffolding are as ubiquitous as tourists.
Anyway, we made it home having avoided rain the whole day, and all bright-cheeked from our scoot down the river. The river - it never lets you down. Even on a grey day it allows you to drench yourself in light and air and history.