"Garboard Strakes says I must always be in the best tide, how do I tell where it is?" asked Tingle.
"Follow Garboard, that's what I do, he's always got a few tricks up his sleeve." "No you don't Luff, you never follow anyone anywhere, in fact Garboard says you're a... well never mind what Garboard says, let's have a sensible answer." "Well old Baggywrinkle always used to say 'When you're behind it's no good just following you have to do something different', but that's another story. "The tide Luff!"
"Well the tide goes up the river for a bit over six hours then down for a bit under six hours. A river has a natural flow down, taking rainwater and sewage etc. to the sea so this adds to the ebb tide which is always a little stronger then the flood. You have a cycle of spring and neap tides, about every two weeks, springs where lots of water comes up the river neap where there is not so much. On spring tides the high waters are higher and the low waters lower. What this means to us is the tide never acts quite the same as it did yesterday. There are some general principles though when the water is flowing along a straight river it will tend to be flowing more quickly in the middle where it is deeper and more slowly at the edges" "So if you are sailing against the tide keep to the edges?" "That's right, but try not to run aground. Around the bends the momentum of the water will push it to the outside of the bend so it will always flow faster round the outside of the bend. So it's generally quicker to sail round the outside of the bend with the tide. When the tide starts flowing it will be a fairly laminar flow, but as it gets stronger you will get a more turbulent flow, it is going round the outside of the bends so fast it may swirl back on the other side of the river" "So how do I tell when it's doing that?" "You have to watch all the signs you can. If you watch the tide here in Anchor Bay you can use the boats on the moorings. When the tide starts to flood they will swing to point downriver, into the tide, as the flood tide gets stronger flowing up Long Reach it will push hard against the Essex shore and start swirling back on the opposite of the river. When that happens you will see the boats swing to point upriver." "So the tides going up on one side of the river and down on the other?" "Yes, more or less, sometimes where the flows meet you can see some signs on he river often the pattern of the ripples will be different or there will be a line of driftwood and flotsam"