SYON REACH NAVIGATION HAZARD AND REDUCED DEPTHS: Mariners are advised that, a portion of the south embankment in Syon Reach has collapsed, leading to a landside which has encroached into the river Thames and AUTHORISED CHANNEL. The landside consisting of earth, debris and trees has REDUCED THE NAVIGABLE DEPTH OF WATER in this area and poses a potential HAZARD TO NAVIGATION. The approximate position is Latitude: 51 28.4154'N Longitude: 000 18.6132'W on the boundary line between Queen's Cottage Grounds and Old Deer Park, as marked on PLA chart 305. Mariners should navigate in this area with great caution, noting the potential reduction in available water depth. This navigation warning will remain in force until such time that this information has been otherwise promulgated.