 Portable or mobile one and two occupant single compartment chambers are not generally intended for routine surface decompression, but may be used in an emergency.A "Saturation System" or "Saturation spread" typically includes a living chamber, transfer chamber and submersible decompression chamber, which is commonly referred to in commercial diving and military diving as the diving bell, "PTC" (Personnel Transfer Capsule) or "SDC" (Submersible Decompression Chamber).The system can be permanently placed on a ship or ocean platform, but is more commonly capable of being moved from one vessel to another by crane.