Weddell seals (Leptonychotes weddellii) were immobilised during expedition PS124 (2021) for the purpose of deployments with satellite transmitters. The deployments (n=10) were located in the Filchner-Outflow-System (FOS), southern Weddell Sea. The seals were captured along the ships' tracks during ahead flights of the board helicopter and immobilised and instrumented on pack ice with Argos-linked (CLS, Toulouse, France) satellite-relayed dive loggers combined with CTD's (CTD-SRDLs, Sea Mammal Research Unit, UK) to investigate their ranging and foraging behaviour in the context of oceanographic features.