20 safety rules of free diving 1. Select your partner and never free dive alone. 2. Never free dive after a scuba dive; allow 12hrs, (Henryâ€™s law). 3. Never â€˜rideâ€™ the flexibility of your ear drum. 4. Always be correctly weighted ;(Archimedes law). 5. Before diving make a complete dive plan together & estimate sea conditions. 6. Remove the snorkel from your mouth before diving. 7. Never exhale under water or forcefully exhale on surfacing. 8. Never dive without adequate rigging & flags. 9. Preserve the correct interval between deep dives; (henryâ€™s law). 10. Never hyperventilate. 11. Avoid too dramatic a turnaround at the end of the descent. 12. Never look down on descent nor up on ascent. 13. Donâ€™t increase pace on last part of ascent; keep calm. 14. Be aware of the danger of empty lung dives. 15. No diving after a samba or blackout. 16. Allow sufficient time for physiological adaptation. 17. Avoid negative suggestion. 18. Never dive when tired or cold; nor with a cold or under the influence of drugs or alcohol. 19. Correct timing for food & hydration is essential. 20. Know yourself.