A dry deck shelter (DDS) is a removable module that can be attached to a submarine to allow divers easy exit and entrance while the boat is submerged.
The host submarine must be specially modified to accommodate the DDS, with the appropriate mating hatch configuration, electrical connections, and piping for ventilation,[1] divers' air, and draining water.
The DDS can be used to deploy a SEAL Delivery Vehicle submersible, Navy divers, or Combat Rubber Raiding Craft (CRRC).
[3] [4] Training is conducted at the purpose-built Chalfont Shore Facility (CSF) constructed by BAE Systems at HMNB Clyde.
[8] The shelters are maintained by a combined effort of Navy divers stationed on the teams and workers of the maintenance company Oceaneering International.