The free surface effect is the technical term explaining the reason superyachts need to empty swimming pools before they sail
It refers to the tendency of liquids to slosh about: to move in response to changes in the attitude of a deck on a superyacht in reaction to sea state caused by waves and wind acting upon the craft.
Refilling the pool can be a lengthy process and some guests get agitated that they cannot use the pool as soon as the yacht is at anchor.
Dutch designers and Naval Architects Cor D Rover Design have they believe found the solution in an idea so good they have patented it
When referring to the free surface effect, the condition of an onboard swimming pool that is not full is described as a “slack“, while a full pool, is said to be “pressed up“.
The concept conceived by Cor D Rover ensures the pool is pressed up before and after the large covering doors are closed and so the problem is eliminated until the yacht reaches her destination when it can be opened at the touch of a button and used immediately.
The clever part of the patent is that the adjustable floor of the swimming pool moves upwards and solves the disadvantage of the free surface effect of the water.
The clever idea of covering a pool means that the extra deck area a closed pool provides can be used for large parties and on-deck sports.
