Hydrofloors® vertically movable floors enable the client to exploit the surface area of a swimming pool by converting the associated terrace or indoor pool room for other uses e.g. recreation, social events, for dining and dancing. The system is near invisible, flexible, rapidly adaptable and safe, being in compliance with relevant national safety standards. The concept is that the floor height of the pool may be elevated to set at any pre-selected water depth such as wading depth for children or a depth suited to those with special needs. This makes the pool itself diverse and multifunctional.