The slow- to ultra-slow spreading Red Sea Rift (<1 – 1.6 cm/yr spreading rate), was the target of two research cruises performed within the framework of the multidisciplinary “Jeddah Transect Project” carried out in cooperation between the Helmholtz Centre for Ocean Research Kiel (GEOMAR) and King Abdulaziz University in Jeddah, Saudi-Arabia (www.jeddah-transect.org). The German R/V Poseidon (cruise P408 in 2011) and the Dutch R/V Pelagia (cruises 64PE350/351 in 2012) were used to map large parts of the Red Sea Rift (RSR) by ship-based multibeam on 5 separate legs, which resulted in an overall coverage of >28,600 km2. New seafloor mapping results include the northern Mabahiss Deep area (25.5°N), large parts of the Nubian-Arabian Rift between 23.3°N and 17°N, some areas of the Danakil triple junction at 16.7°N, as well as two crossings of the Danakil-Arabian Rift at 16.5°N.