Carsten Rehder is traditionally active in maritime trade organisations. Thomas Rehder is board member of the German Ship Owners Association, past president of the European Ship Owners Association ECSA,  as well as past member of the board of the DNV GL Group in Oslo.

Carsten Rehder is also member of the German Shipowners' Defence Association, Trampko (an association of hanseatic ship owners) and Hamburg and Bremen Shipbrokers´ Association.