A wearable device for monitoring and providing real-time feedback about a swimmer's body motion and performance, in particular, body orientation and forward speed, is provided. The device comprises a three-axis accelerometer, optionally a three-axis gyroscope, a memory, and a microcontroller configured to process the sensor input, calculate a swimmer's performance and provide feedback to the swimmer through an output. The output can be an earpiece or a swimming goggle with a digital display.
