But according to Dr Paul Kingston, from the Centre for Marine Diversity and Biotechnology at Heriot-Watt University, Edinburgh, the problems are minimal.
The report was funded by the Joseph Rowntree Foundation but carried out by Professor Philip Leather of London's South Bank University and Professor Moira Munro of Heriot-Watt University in Edinburgh.
It just became possible, thanks to a laser camera developed by physicists at Heriot WattUniversity in Edinburgh, UK. You can pretty much see how it works from the images above -- laser beams are bounced off the target and the duration of their return journey is measured precisely enough to detect millimeter depth changes even at extreme distances.