Marinelands are entertainment companies whose main stars are marine mammals. Based on fieldwork conducted in a European aquatic park, this paper analyses how such a company deals with the many affects and emotions that intersect there: the dolphins’, the public’s, the trainers’ and the anti-captivity activists’. The first part of the paper shows that parks are engaged in a deliberate policy of affects that is used to legitimate captivity, in an international context that is globally unfavourable to it. The second part deals with trainers’ interactions with dolphins and document the affective work that trainers operate on themselves and on their animals in order to «produce» a dolphin that is eager to work and which they can trust.