Seabed and sea surface light time series from the Bay of Brest, France, 2011-12 dataset https://portal.medin.org.uk/portal/start.php?tpc=006_b28398454aeb5677b95eabe4875d375c These seabed and sea surface light data were collected in the Bay of Brest, Brittany, France, in 2011-2012. R.V. Albert Lucas and smaller vessels were used for deployment and recovery of the seabed light sensor instrumentation. Corresponding time series records of seabed and sea surface irradiance were collected. Water depth above, and water temperature at the position of the sensor were also recorded. The data were collected as part of a project studying the effect of tidal variations in water depth and clarity on the light that reaches the seabed (Roberts et al., 2014; Roberts, 2015). They were collected by Bangor University scientists (primarily E.M. Roberts), assisted by contacts at the Centre d'Etudes Techniques Maritimes et Fluviales (CETMEF, now Cerema) and the Institut Universitaire Europeen de al Mer (IUEM). 20180206 20170530