From my article:
Advanced Wreck Diving - Workshop Notes
Required Diving Skills
Recreational wreck divers should possess the following competencies before penetrating wrecks:
- Buoyancy Control. Ability to maintain +/- 50cm of target depth, whilst otherwise task loaded
- Trim. Ability to maintain flat horizontal trim, with slightly head-down positioning.
- Propulsion. Ability to utilize non-silting fin techniques, including frog kick and modified flutter kick.
- Control. Ability to demonstrate positioning control without reliance on hands. Efficient use of helicopter turns and back kicks for maneuverability within confined spaces.
- Streamlining. Divers’ equipment demonstrates effective streamlining, efficiency and adequate redundancy, with no obvious entanglement hazards and minimum failure points.
- Gas Management. Ability to accurately plan and manage gas requirements for the planned dive, including contingency reserves.
- Dive Planning. Ability to precisely plan a no-decompression dive, conduct effective risk assessment and confirm effective contingency/emergency plans prior to water entry.
- Navigation. Ability to effectively navigate back to the start point, using compass and natural navigation techniques.
- Buddy/Team Skills. Ability to plan dives and follow those plans in a coordinated way with a diving buddy/team, including the ability to conduct effective emergency drills. Buddy diving.
- Situational Awareness. Ability to maintain awareness of depth, time, no-decompression limit, surroundings, navigational location and buddy/team, whilst otherwise task loaded with specific skills.
I think those requirements are necessary for any penetration activities, recreational or technical.
In addition, for penetration/overhead environment diving, the ability to effectively lay & follow guidelines needs to be ingrained in muscle memory. This demands
more training than given in the solitary penetration dive on a recreational wreck course. I typically find that 6+ training dives in line-laying/penetration are needed to get the average diver to a level of acceptable fluidity with line laying/following.
Where the diver intends to operate beyond the 'light zone', past restrictions or at depths where narcosis may be present (END 30/100ft), then the emphasis changes from recreational to technical level diving.
These are the limits I recommend with recreational wreck penetration:
Recreational Wreck Diving Limits
Recreational wreck divers should observe the following limits to penetration of wrecks:
- One continuous guideline
- No restrictions*
- No decompression
- 30m max depth
- No complex dives, including jump lines, gap lines or permanent lines
- Rule of thirds air management on single/double tanks
- Max linear distance to surface (horizontal plus vertical) is 40m/120ft
- Within the ‘light zone’, where natural light penetrates and illuminates
- Ability to clearly see the exit at all times
- No severe risk of silt out
*A restriction is defined as a space too small for 2 divers to pass through simultaneously whilst sharing air.
Technical wreck diving demands the need to operate manifolded/isolated doubles, the ability to plan/conduct decompression and the training necessary to perform a collection of guideline drills in low/zero visibility (
lost line, entanglement, lost buddy, broken line etc). In that respect, the diver should ideally have completed AN-DP-ER & Advanced/Technical Wreck training.
The requirement for trimix depends entirely upon the depth range of the wreck/s that will be dived. I think an END of 30m/100ft is ideal, but this is ultimately dictated by the divers' comfort levels, tolerance and experience.
I agree completely!
