Through different projects, the Center for Topographic studies for the Ocean and Hydrosphere (CTOH) contributes largely to advances in coastal altimetry and to its use in coastal applications. It has developed the X-TRACK software dedicated to the reprocessing of coastal altimetry data. X-TRACK is now a mature sea level product distributed worldwide by AVISO+ (https://www.aviso.altimetry.fr), cited in many scientific publications. It consists in long time-series of SLA from most altimetry missions, processed homogeneously, but also...