The NOC have been at the forefront of research and development of novel environmental mapping capabilities using marine radars for well over two decades. The high-resolution X-band radar Temporal Water Line mapping (TWL) method, developed at NOC (Bell, 2015), is now provided as a commercial service by Marlan Maritime Technologies Ltd. Ongoing development work at NOC has adapted the TWL method to use a combination of SAR and Optical imagery from the ESA Sentinel satellites to estimate intertidal bathymetry over large spatial extents. This per-pixel method provides a unique capability for ongoing monitoring of large spatial extents at decimetre scale accuracies.