12th October 2026 | by Sarah Taylor
NAVIGATION
RIVER ROACH- Blackedge Point – Temporary ‘Special Mark’ Yellow Buoy.
Mariners are advised that a temporary ‘Special Mark’ yellow buoy with light sequence
Fl Y (5) 20s is to be deployed in approximate position: Please click on link for map.
51° 35.126 N
000° 47.991E
The buoy marks a seabed frame containing a current monitoring instrument to provide data to inform water quality modelling for Anglian Water Ltd and is scheduled to remain in this position for approximately 30 days.
Information
APEM Group Ltd has commissioned ABPmer to undertake a monitoring programme within the transitional and coastal (TraC) waters of the River Roach, River Blackwater and River Colne.
As part of this programme, ABPmer will be deploying CTD instruments (to observe temperature and conductivity/salinity) at five locations in these rivers for a 30-day period. The deployments are planned to take place on approximately 13-15 October 2026 and will be recovered approximately 30 days later.
During deployment/recovery operations, the vessel Jean T will be on respective locations for an approximate 1-hour period. When stationary other vessels are requested to pass at a safe speed and distance. VHF Channels 11 and 16 will be monitored throughout deployment and retreival operations.
The monitoring instruments will be secured within a seabed frame which will protrude above the seabed by 0.5 m in water depths ranging between 0m and 3.0m below Chart Datum. The frames will be secured to a 250kg sinker weight by weighted groundline. From the weighted groundline will be a riser chain to a surface marker buoy