Bathymetric ENCs (bENCs)
Port of London ENCs are compiled with 1 metre contour intervals allowing for detailed safety contour delimitation. In particularly sensitive and changeable areas, even greater definition can sometimes be required. Highly accurate bathymetry from the most recent survey can be compiled into a Bathymetric ENC (bENC). In the case of the PLA, the key channels and berth approaches are now all covered at 0.5m contour interval.
As bENCs are unofficial products, the compiler/commissioner can choose a contour interval that best suits the area and its navigational challenges. For instance, the Port of Rotterdam uses 0.25m intervals within high density (HD) ENCs that are generated by automatic scripts. At appropriate zoom bENCs, when enabled, overlay the existing display on the ECS giving important extra, and often more current, bathymetric detail. Aside from metadata, they contain only bathymetric features (soundings, contours and depth areas) which overlay. Base display items "shine through" from the underlying ENC. This simplicity means compilation time is usually much faster than that of an ENC. Sorlingas currently maintains a folio of 30 bENCs for the PLA.
