Wednesday, 8 June 2011

Three Hazards 2. Weed

Getting tangled with a submerged supermarket trolley will probably damage your propeller. Less obviously, however, anything wrapped around the propeller or the prop shaft will interfere with the effective power of your engine by changing its flow.
It's wise to check your prop at the end of each day's boating; more frequently if there are visible signs of floating weed or debris, or a feeling that you're not going as fast as you might expect. That's what the weed hatch is for. It avoids you having to dive over the side every evening ....

You MUST switch off the engine - and we always take out the key as a double precaution. Unscrewing the top handle releases the metal cross bar so you can delve in the water below. With luck the light will be right and you can see your propeller and shaft gleaming clearly. More usually it will be your fingers feeling around in the cold and murky depths. Take off any weed, stalks or any foreign matter; rarely, a knife might be needed.
Here Alan is cutting away some fishing line while Patience is in dry dock.
So, why weed? Well, our recent trip down the Ouse was mostly clear of surface weed on the way out, but several days of hot sun had caused the blanket weed (spirogyra adnate) to spread and at one point a combination of a mass of weed entangled on the prop shaft and a strong wind blowing across a narrow stretch of river both pushed us towards the bank and seriously reduced our power. 

The result was we had insufficient power to prevent us drifting to the bank - where more weed lay in wait for us. 
So we stopped the engine, cleared the prop and restarted - but the weed simply re-tangled itself. This time we cleared the prop but poled away from both bank and weed before re-starting the engine. This is not a situation that a single-handed boater would enjoy and once more emphasises the importance of long and strong poles and hooks!
On the bright side, swans and ducks seem to enjoy it....

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