The SAS Assegaai museum submarine in Simon’s Town aims to gives visitors the opportunity to experience life in a submarine with its’ perfectly preserved interiors and expertly guided tours. 
Decommissioned in 2003, the French-built submarine SAS Assegaai has been lovingly restored by a group of retired and in-service naval staff who, with the blessing of the South African Naval Museum, have opened her up to the general public.
The guides explain how the submarine dives and how it surfaces at sea and you get to know many interesting facts about submarines. One of the more fascinating aspects being the generation of fresh air for the crew when dived. The knowledge of the ex-submariners on board the submarine is extensive and their passion for this grande dame is quite contagious!
Follow this link for more information: http://goo.gl/KDwgBN