Here Exley consolidated his experiences and accident analysis into a manual of sorts. This was the first time the basic rules of cave diving were published. Rules such as:
- Maintain a continuous guideline to the exit
- Keep one third of your starting gas volume in reserve
- Carry at least lights
These were shared along with the recommendation to use a 1.25-1.5 m/4-5 ft hose to facilitate gas sharing.
Other pro tips like not stirring up silt and not exceeding one’s level of training and experience are great advice from which all divers can still benefit.