wall 22 of the spa 10 is buried underground access to the equipment bay 44 is easily and conveniently accomplished through the top access cover 50 in the coping 26 consequently there is no need to build a retaining wall or the like around the spa 10 before it is placed in the hole however if the appearance of an in ground spa is desired and the user wishes to keep the option to move the spa 10 in the future such a conventional retaining wall could be built advantageously since the equipment bay 44 is accessible at the tope of the spa 10 only a small clearance is necessary between the spa side wall 22 and the retaining wall when the spa 10 is installed above ground level there will be some lateral forces against the walls comprising the reservoir 28 and the outer wall 20 of the shell 18 for example the weight of the water 12 in the reservoir 28 creates an outward lateral pressure against the reservoir walls and contributes to the overall weight of the spa 10 and thus the forces exerted on the side wall 22 supporting the spa even more significant however is the lateral pressure against the outer wall 20 caused by the earth 16 when the spa 10 is.