tillergirl
Well-Known Member
Data is crunched and the new chart is up either at www.eastcoastsailing.co.uk or on my site.
Thanks to Colin (official forum lurker) for helming or pressing tillerpilot buttons all day.
In a nutshell: Depths have reduced and the width of the swatchway is narrowing. That's the bad news. the good news is its still viable - it must be because we trolled back and forth over it for an hour and a half yesterday!
The knoll of the Middle Sunk does not appear to be intruding any more than last year. As it was low water (neaps) when we were there yesterday we couldn't sound over the edges leading up to the drying bits but the closer we got to the drying bit, the more the data corresponds (generally) with last years data. Mystique's knoll is still there. But on the west side of the swatch, there is a definite sign of the sand building up from the direction of the old SW Sunk beacon. But there is at least 2.2m there at chart datum by my calculations - well there was yesterday. I can't guarantee how long that would remain obviously. The soundings are 'worse case'. So I am hoovering up a sounding every 3 seconds and going over relatively slowly which provided 2316 soundings upon which the chart is based (yes I used less than 1%!) Where there is a line of soundings going 2.5, 2.4, 2.5, 2.4, 2.1, 2.6, 2.5, 2.4, I will have used the 2.1. The echo sounder would have averaged out the 2.1 but not the NMEA data.
We noticed a definite south going tide through the swatch towards the end of the ebb. It's very noticeable on the NMEA data.
I think a general message is don't cut the corner if you are using this swatchway. Go down the main channels (Barrow or Black Deeps) and make a definite turn in through the swatch.
Hope it helps. Good luck peeps
Thanks to Colin (official forum lurker) for helming or pressing tillerpilot buttons all day.
In a nutshell: Depths have reduced and the width of the swatchway is narrowing. That's the bad news. the good news is its still viable - it must be because we trolled back and forth over it for an hour and a half yesterday!
The knoll of the Middle Sunk does not appear to be intruding any more than last year. As it was low water (neaps) when we were there yesterday we couldn't sound over the edges leading up to the drying bits but the closer we got to the drying bit, the more the data corresponds (generally) with last years data. Mystique's knoll is still there. But on the west side of the swatch, there is a definite sign of the sand building up from the direction of the old SW Sunk beacon. But there is at least 2.2m there at chart datum by my calculations - well there was yesterday. I can't guarantee how long that would remain obviously. The soundings are 'worse case'. So I am hoovering up a sounding every 3 seconds and going over relatively slowly which provided 2316 soundings upon which the chart is based (yes I used less than 1%!) Where there is a line of soundings going 2.5, 2.4, 2.5, 2.4, 2.1, 2.6, 2.5, 2.4, I will have used the 2.1. The echo sounder would have averaged out the 2.1 but not the NMEA data.
We noticed a definite south going tide through the swatch towards the end of the ebb. It's very noticeable on the NMEA data.
I think a general message is don't cut the corner if you are using this swatchway. Go down the main channels (Barrow or Black Deeps) and make a definite turn in through the swatch.
Hope it helps. Good luck peeps
