Dive log


A dive log is a record of the diving history of an underwater diver. The log may either be in a book, locally hosted software, or web based. The log serves purposes both related to safety and personal records. Information in a log may contain the date, time and location, the profile of the dive, equipment used, air usage, above and below water conditions, including temperature, current, wind and waves, general comments, and verification by the buddy, instructor or supervisor.
In case of a diving accident, it can provide valuable data regarding diver's previous experience, as well as the other factors that might have led to the accident itself.
Recreational divers are generally advised to keep a logbook as a record, while professional divers may be legally obliged to maintain a logbook which is up to date and complete in its records. The professional diver's logbook is a legal document and may be important for getting employment. The required content and formatting of the professional diver's logbook is generally specified by the registration authority, but may also be specified by an industry association such as the International Marine Contractors Association.

Contents of the logbook

Typical fields in a recreational diver's log book would be the following:
A more minimalistic log book for recreational divers who are only interested in keeping a record of their accumulated experience, could just contain the first point of the above list and the maximum depth of the dive.
A commercial diver's logbook may be considered a legal document, and may contain more information, both about the diver, and about each dive recorded. It is generally verified by the diving supervisor for each diving operation.
It may include the following sections:
  1. Personal details of the diver
  2. Medical certificates of fitness to dive and notes
  3. Qualifications and certificates
  4. Training record
  5. Competence assessment record
  6. Record of dives
  7. Medical records illness or injury
  8. Cumulative diving experience
The record of each dive may contain:
  1. Date of the dive
  2. Signature of the diver
  3. Name and address of the diving contractor
  4. Dive location
  5. Vessel or installation from which the dive is done
  6. Type of dive
  7. * For bell bounce or surface dives:
  8. ** Maximum depth of the dive
  9. ** Time left surface or started pressurisation
  10. ** Bottom time
  11. ** Time that decompression was completed
  12. ** Details of any surface decompression, including surface interval and time in the chamber
  13. ** Accumulated bottom time
  14. ** Accumulated total time under pressure
  15. * For saturation dives:
  16. ** Storage depth
  17. ** Maximum depth of dive
  18. ** Bell lock-off time
  19. ** Time that diver left bell
  20. ** Time that diver returned to bell
  21. ** Lock-out duration
  22. ** Bell lock-on time
  23. ** Accumulated number of lock-outs
  24. ** Accumulated total time under pressure
  25. Details of work done and equipment used:
  26. * Breathing apparatus used
  27. * Breathing mixture used
  28. * Work description, equipment and tools used
  29. Name of decompression schedules used
  30. Notes regarding any decompression incident or other illness or injury
  31. Any other relevant comments
  32. Name and signature of the diving supervisor for the dive
  33. Diving contractor's official company stamp

    Dive log software

Usually diving computer manufactures have their own software to view and analyze diving logs, but there are also open source versions.
Subsurface is free open source dive log software started by Linus Torvalds, which is compatible with several makes of downloadable diving computer.