Scientists from around Europe gathered from the 26-28 of March 2024 in Delft for the official Kick-Off Meeting of the new Horizon-Europe-funded LandSeaLot project. Coordinated by the Dutch research institute, Deltares, the project aims to bolster observation capabilities within European river mouths and estuaries. The four year project comprises 20 partners spanning 12 European nations and will bring together communities involved in river to coastal sea as well as carbon observing Research Infrastructures, with citizen science networks and the consortium’s leading scientific expertise. The project will bring novel approaches to help achieve the goals of the Water and Marine Strategy Framework Directive as well as the EU Mission “Restore our Ocean and Waters by 2030” and the wider objectives of the EU Green Deal.