Ever had your dive computer throw false alarms mid-dive because of unreliable biometric readings? In this episode, Marcus Okafor shares how a malfunctioning heart rate sensor nearly cut short a wreck dive at 110 feet—and breaks down the complete calibration process to ensure your biometric data is actually trustworthy. Whether you're running a Garmin Descent or Shearwater Peregrine, you'll learn how to establish accurate baselines, clean optical sensors properly, and verify readings before every dive. This one's for intermediate divers ready to move beyond factory defaults and get real data from their gear.

• Factory default settings assume you're a 30-year-old male with average fitness—if that's not you, your workload calculations and heart rate thresholds are likely way off from the start.

• Measure your true resti ...