Using Sculling Coach requires the phone securely mounted in the boat. There are several waterproof case/mounting systems that work well - the one displayed is made by Armour-X. Other good systems include ProShot and LifeProof.
To activate the heart monitor, ensure your heart monitor is properly positioned on your chest. Then go to the iPhone Settings->Bluetooth and select your heart monitor from the list of Bluetooth devices. Then inside the ScullingCoach application, select Settings and choose heart monitor switch setting.
First Stroke - When activated the app will start recording only when a stroke is detected.
Stroke Threshold - a way to fine tune the stroke detection sensitivity. Use the slider to change the value from 1.10 to 1.25. Default is 1.19