Title: Long-term underwater stays matters. Objective: The aim of this thesis is to compile the issue of long-term underwater stays from their preparation to safe descent and their transfer to a real project. Methods: On the basis of research of diving literature on the given topic thoroughly make preparations together with pilot experiments. Then implement, secure and evaluate the One week project as a long-term underwater stay lasting 7 days. Use interviews with participants to get necessary information for adequate preparation and feedback. Results: With the help of professional literature, we managed to prepare, secure and realize a long-term underwater stay in the planned duration of 7 days. The domestic record was thus humbled. Keywords: aquanaut, bell, habitat