A swimming simulation system is provided comprising a dynamic bench, an arm cable pulley system coupled with hand grips, a foot cable pulley system coupled with a foot hold, and a resistance mechanism with attached gearing systems. The method also includes receiving integrity information from the secondary server and checking the integrity information against the integrity criteria. Weighted decoding is effected independently and cycle by cycle: it starts at a robust location, with a relatively high likelihood, and terminates at a weak location, with a weak likelihood, ignoring the concept of time. Also contained in the enhancer is a transmitter sub-system operable with the receiver sub-system that converts the signal from the receiver subsystem to a second predetermined frequency band and further amplifies the signal.