Abstract: The invention concerns an underwater immersion installation (10) comprising at least one immersion pod connected to means (16, 18, 20) for lifting and lowering same, and an assembly of breathing and acoustic attachments borne by the pod (14) and separable therefrom when the pod is immersed, each breathing and acoustic attachment including a headgear mounted on a vest urged to be positioned on the chest of a user and being provided with a conduit supplying the headgear with air delivered from the surface and listening/communication means connected to complementary means.