Cold water: shock, 1-10-1 and survival times
Cold water is any water under about 60 °F (15 °C), and cold shock can start in water as warm as 77 °F (NWS). Enter a water temperature to see the published timeline.
The 1-10-1 principle
About 1 minute of cold shock and gasping, about 10 minutes of useful muscle movement, and up to about 1 hour before unconsciousness from hypothermia (Canadian Safe Boating Council). The National Center for Cold Water Safety cautions that these are rough figures, that incapacitation can come in as little as 2 minutes, and that survival charts can give false confidence (NCCWS).
What changes it
- A worn life jacket keeps your airway clear through gasping and after your arms stop working (USCG).
- A wetsuit or drysuit reduces cold shock and slows heat loss; dress for the water, not the air (NCCWS).
Educational summary of the cited sources, not a safety guarantee. Check local conditions and wear a life jacket.