We've been aboard for a few months now. And although this summer the weather's been as amicable as a thirsty wasp trying to see into the earhole of a neurotic woman holding a jug of Pimms on the back of a boat, there's been little in the way of wind. At least outside the boat. I can't vouch for the flammable offerings induced by my leftover elephant-foot-kebab stirfry with extra chillies, though.

We're blessed with a wind turbine on the roof, as planted there by the previous owner. We've erected said turbine a few times to see if the little green light in the cabin would ever turn on to indicate that it's actually charging the batteries, and to prove that it's not designed merely for decapitating passing chiffchaffs. Indeed it has glimmered into life for a second or two, but we assumed that it's reluctance to do this with any real welly was probably due to the huge crack down the front of the turbine, caused by two run-ins with a bridge (the latter involving a very friendly wasp, a very neurotic woman and much brickdust in an otherwise perfectly mixed jug of Pimms). But the trouble was equally likely to have been that the wind had yet to be strong enough to spin the turbine at over 5 knots - the minimum charging speed. That was until last night...

A blustery, drizzly typically autumnal evening was too good an opportunity to miss. So with Kev precariously surfing the roof of the boat like Keanu Reeves in Point Break, (only with slightly less money and infinitely better acting skills) and with the potential of a Weil's Disease dunking with every rocking gust; and me teetering on the gunwhales hooking up the guy ropes and weaving invading tree branches under them to prevent instant mulching; we rigged the turbine up.

How excited we were when we withdrew to the back cabin to find the little green light glowing! In celebration, we retreated to the other end of the boat to watch DVD's of Doctor Who (in order to drain what little energy the turbine was providing).

By about 11pm, hot water bottle in-hand, it was time for beddybyes. "Unusual," thought I as I turned off the strangely squeaky battery-powered bathroom air freshener, (guaranteed to provide a spicy vanilla freshness and bouts of insomnia/chemical blindness every 9, 18 or 36 minutes). "I can hear whalesong".

I promptly called Kev over. "Nah" he said "that's not a whale"

"I'm telling you, that's the noise a whale makes, if ever I heard a porpoise, and it's coming from our ceiling!" quoth the spicy vanilla scented one, rubbing her stinging eyes.

"That's not whalesong" replied Kev "That's a perfect B flat" and promptly burst into song.

Even in our dalek-afeared frame of mind, it didn't take us long to link the noise with the turbine. A little concerned, we put our shoes on with our jimmyjams and braved the rain to check the wind turbine from the towpath:

Outside: All was quiet. Inside: Free-bloody-Willy.

I had erstwhile read about vibration noise from wind turbines, but never expected it to resonate sooo loudly, or so tunefully, nor to be pitch perfect. Incidentally B Flat really annoys alligators, which could prove useful on the Regents Canal, on a windy day.

B Flat is also the note created by gas emerging from a black-hole. Not disimilar to the after-effects of my leftover elephant-foot-kebab stirfry with extra chillies, I fear...