tillergirl
Well-known member
For those interested, Gladys and I reported that the SW Sunk was still there and feasible this Spring but there was an 'object' on the north side of the swatch. I marked its position and it is marked on the current download.
Inset wreck image by Roger Gaspar, on Flickr
At the time, we and the forum speculated about the object: unfortunately I could not report how much water was over the object. However, our survey shew that the general depths of NE side of the swatch had significantly deepened - 0.5 to 1.0m+ water at least perhaps exposing debris.
Now courtesy of the Port of London Authority I have been sent data which clarifies things. First the swatch remains fine. the SW knoll is pretty stable (i.e. it hasn't moved much, if at all) but the ENE side of the Middle Sunk has continued to shed sand thus generally giving us a nice wide western entrance (or exit). The PLA confirm that the minimum depth at Chart Datum is 3.3m. The western side remains deep with 7m+ while the eastern side shallows to a minimum of 3.3m. So that is good news.
The object found is part of a wreck. Indeed there are three pieces. The largest has 2.4m water over it at CD while the seabed around it is approx 1.8m lower (i.e 4.2m CD - we had 3.9m there earlier in the year). There is also is a scour hole to the south which is 8.9m at CD! Eek.
I think we should commend the PLA for troubling to bother to provide this sort of data. The PLA do want and need to maintain a strategic overview of the state of the sand banks but no ship is hardly going to want to go there. Also it has been a busy year for them so providing us the detailed data is really nice of them. I have been provided with the xyz data so in a couple of days I will post a new chartlet as soon as possible. Of course Gladys and I will go back in the Spring, hopefully on the first Spring tides in May, the week commencing 6th May (I haven't told Gladys yet).
Inset wreck image by Roger Gaspar, on FlickrAt the time, we and the forum speculated about the object: unfortunately I could not report how much water was over the object. However, our survey shew that the general depths of NE side of the swatch had significantly deepened - 0.5 to 1.0m+ water at least perhaps exposing debris.
Now courtesy of the Port of London Authority I have been sent data which clarifies things. First the swatch remains fine. the SW knoll is pretty stable (i.e. it hasn't moved much, if at all) but the ENE side of the Middle Sunk has continued to shed sand thus generally giving us a nice wide western entrance (or exit). The PLA confirm that the minimum depth at Chart Datum is 3.3m. The western side remains deep with 7m+ while the eastern side shallows to a minimum of 3.3m. So that is good news.
The object found is part of a wreck. Indeed there are three pieces. The largest has 2.4m water over it at CD while the seabed around it is approx 1.8m lower (i.e 4.2m CD - we had 3.9m there earlier in the year). There is also is a scour hole to the south which is 8.9m at CD! Eek.
I think we should commend the PLA for troubling to bother to provide this sort of data. The PLA do want and need to maintain a strategic overview of the state of the sand banks but no ship is hardly going to want to go there. Also it has been a busy year for them so providing us the detailed data is really nice of them. I have been provided with the xyz data so in a couple of days I will post a new chartlet as soon as possible. Of course Gladys and I will go back in the Spring, hopefully on the first Spring tides in May, the week commencing 6th May (I haven't told Gladys yet).
