Nautilus

# Nautilus -- Apnea & Breath-Hold Training Nautilus turns your Garmin watch into a dedicated dry-land breath-hold trainer. Record full apnea cycles with live heart rate and pulse oximetry, follow CO2/O2 tolerance tables, or push for a new personal best -- all saved as a FIT activity that syncs to Garmin Connect. Built specifically for freedivers, spearos, and anyone doing static breath-hold work between dive sessions. ## Key features - Configurable countdown with synchronised vibration cues - Live heart-rate and SpO2 streaming during every hold - LAP-button workflow: tap when you need to breathe, the watch handles rest timing - Four cycling stat screens during both hold and rest phases - Four training modes: Basic, CO2 table, O2 table, Max hold - Custom FIT fields per record / lap / session so Garmin Connect shows hold duration, min SpO2, longest hold, totals - Activity tagged as Apnea Diving so it lands in the right category in Garmin Connect - Optional audible tones, silent-training mode, and backlight-hold ## How to use it 1. Open Nautilus from your activities list. 2. Press *START* -- a 10-second countdown vibrates each second; the last three seconds vibrate stronger. 3. Hold your breath. The big timer counts up; HR + SpO2 stream live underneath. 4. Press *UP* / *DOWN* (or swipe on a touchscreen) to cycle four hold screens: - **Timer** -- big elapsed-hold + live HR/SpO2 - **Live vitals** -- this hold's running min / max / avg HR and min SpO2 - **Session** -- reps done, best hold, total hold time, current timer - **vs Last** -- previous hold's duration, HR range, min SpO2 for comparison 5. Press *LAP* (lower-right button) when you need to breathe. A 2-minute rest begins. 6. Cycle four rest screens with *UP* / *DOWN*: Rest timer, Hold vitals, Session totals, Recovery (current HR vs peak). 7. The next countdown auto-starts. Repeat for as many rounds as you like. 8. Press *START/STOP* when you're done -- the FIT activity is saved and syncs to Garmin Connect. ## Training modes - **Basic** -- fixed countdown and fixed rest; unlimited rounds. - **CO2 table** -- constant hold time, rest shrinks each round by your configured step. Trains CO2 tolerance. - **O2 table** -- hold target grows each round, rest stays fixed. Trains O2 tolerance. - **Max hold** -- single round; the LAP button saves immediately. For benchmarking.

v1.0 - Initial release - Full breath-hold tracking with a configurable countdown and rest cycle - Live heart-rate and pulse-oximetry capture throughout the activity - LAP-button workflow: end a hold, skip a rest, or skip a countdown - Four cycling stat screens during both hold and rest phases (UP/DOWN buttons or touchscreen swipe)