A training aid for a swimmer includes a housing. The housing is sealed so that the housing is water tight. A coupler is coupled to the housing and is configured to couple to a swimmer's goggles to couple the housing to the goggles. A power module, a microprocessor, and a sensor are coupled to and positioned in the housing. An indicator is coupled to the housing. The microprocessor is operationally coupled to the power module. The sensor and the indicator are operationally coupled to the microprocessor. The sensor is configured to detect motion of the housing so that the microprocessor is positioned to determine a speed of the swimmer and to compare performance values of the swimmer relative to target values. The microprocessor is positioned to selectively signal the indicator to notify the swimmer of a difference between the performance values and the target values.