A business plan represents the justification for entering a particular business venture. Its preparation requires extensive knowledge, skills in data collection, and analysis. Since the plan needs to highlight the advantages and disadvantages of entering the business, it is necessary to invest significant time to collect the most accurate data possible. This paper provides a detailed elaboration of an entrepreneurial project using the example of investment in sensory deprivation therapy. Sensory deprivation therapy, also known as float therapy, is becoming an increasingly popular method of relaxation and stress treatment in today's world. The therapy involves lying in a special chamber filled with salt water and magnesium, creating a sensation of floating. This therapy has many potential benefits, including reducing anxiety, improving sleep, reducing pain, and enhancing mental focus. The aim of the research was to assess the profitability of entrepreneurs entering this business and to estimate when the return on investment could be expected. The first part of the paper consists of a theoretical section addressing the topic of entrepreneurship in general, while the second part presents a detailed elaboration of the entrepreneurial idea focused on sensory deprivation therapy.