AT~SEA is a 3-year European project within FP7 (NMP work programme). The project aims at the development of advanced technical textiles in order to demonstrate the technical and economical feasibility of open sea cultivation of macroalgae (seaweed).The project targets the development of novel textile materials for 3 different elements of the aquatic biomass cultivation farms:• Advanced 3D multilayer textile substrates for seaweed cultivation• Advanced textile based cables and connections for positioning and anchoring of the 3D multilayer textile substrate• Advanced coated textiles for flexible and light-weight floatation tubes, as well as for storage and transportation tanksBy reaching these goals, AT~SEA targets at the development of innovative offshore textile products. Further, it wants to stimulate bio-energy production from seaweed by enabling open sea large scale cultivation and harvesting.The choice for macroalgae based aquatic biomass cultivation in AT~SEA is based on the following reasoning: 1) 70% of the earth’s surface is ocean, thus there is a huge potential for biomass growth, 2) macroalgae grow much faster than conventional crops on land, 3) by producing the biomass at sea we avoid the discussions about land food crops being used as fuel/energy source. This is the so-called food-energy nexus.It is an important challenge as today the total worldwide energy consumption is ca. 480 exajoules (EJ, 480 × E18 J). Approximately 90% is derived from the combustion of fossil fuels. Fossil fuels, i.e. coal, oil and natural gas, are limited in supply and will one day be depleted. As a result the quest for renewable energies started decades ago. These are energies generated from natural resources such as sunlight, wind, tides, etc. but also from industrial or urban waste and biomass. Induced by numerous studies and energy conferences, the 27 member states of the EU decided in 2007 that 20% of our energy should come from renewable sources by 2020 (Lisbon Treaty). Biomass energy, being the oldest source of renewable energy, is generally acknowledged as one of the most promising. The technology is based on converting biomass material (plants and animal waste) into energy (i.e. heat, electricity and/or chemicals, like methane gas, butanol, etc.).The project consortium is well-balanced and consists of 11 partners from 8 countries (6 SME’s, 4 RTD’s and 1 LE). In order to facilitate a successful project, the consortium covers a broad range of required competences, i.e. textiles, biology and biotechnology, offshore engineering, and renewable energy. Since the focus is on the development of textiles, 6 out of 11 partners stem from the textile sector.