Roger Gaspar (crossingthethamesestuary.com) reports on 21st March 2016:
I have had information from a couple of yachtsmen this month who specifically independently tried the SW Sunk swatchway on the 6th and 17th March respectively. On each occasion a serious spot of shallows was found just on or south of the rhumb line between the waypoints as shallow at 0.1m low water rather than 3.5m expected. It may be that the swatch has migrated north-east and it is possible to cross a few hundred yards further that direction but there is no data at the moment.
I will be re-surveying the area but it will be early May before I can do it (wooden boats need warmth to be painted - and I am fettling some woodwork at the moment). I shall ask the PLA if there is more information recently but I suspect there isn't. Incidentally the PLA has supplied their 2015 survey of the Middle Sunk area. I've drawn the chartlet and frankly the Middle Sunk based upon 2015 isn't the best.
It is possible but a little brave - the swatchway wanders like a dog's back leg and close to the unmarked wreckage of the old Sunk Beacon and a drying area right north of where we would have wanted to head! So not recommended to use either the SW Sunk or the Middle Sunk until tried. The Little Sunk crossing has been successful and traditional that is pretty stable.
As soon as I have information I shall make it clear in the meantime I shall provide an Update of the chartlet for the Middle Sunk tomorrow, 22nd March, 2016.
Roger
