How University of London Boat club use Ludum 

Hi Andrew, thanks for your question. There are two ways to do this, one is for the athlete to connect their ludum account to their device (Garmin, polar etc) and then Ludum will import their HR data after the session - they wouldn't need their phone in the boat to do this. The second is to record the data using the Ludum app itself by pairing a heart rate strap with their phone but like you say this would require taking their phone in the boat with them.