I am not a certified cave diver, so am not qualified to comment in depth regarding caving. A few dives in the Ginnie Springs area, however, and some reading and discussions with cave divers have led me to conclude that running line in caves is significantly different than running line in wrecks.
Primarily, inside caverns and caves there are far fewer instances involving jagged metal edges, wire and pipe debris projecting down from "above" (from whatever it once was) to entangle the line, and the general abrasive patina that sea life lends to metal surfaces and shapes of all types. Fresh water cave environments are more conducive to use of thin braided nylon line. In many wrecks moreover there are strong currents and eddies that move the line back and forth repeatedly (over the rough edges). Caves represent a more static environment, along a wider range of environmental parameters.
I do not wish to start any arguments. I'm aware my comments may ignite the sort of discussion that 'solo diving' (and other hot button topics) tends to elicit. But there are debates among wreck divers regarding the wisdom and effectiveness of relying on line inside wrecks. Some prefer to proceed very slowly and learn the wreck over a large number of dives. There have been threads in the tec section on wreck diving which discuss this at greater length.
I am not recommending anything to anyone. But for new, aspiring wreck divers - I simply note that there are wrecks that do not lend themselves well to the use of penetration lines. Because of the greater likelihood of the line parting (at a point where it abraids against a sharp edge) under any sort of stress placed upon it (such as might occur were the diver to become entangled in the line), the running of penetration line in wrecks is - IMHO - an extremely advanced technique.
Also, those of you who are wreck divers can offer much more eloquent testimony than I to the fact that, while caves silt out also, the oxidization occurring inside wrecks causes passageways to silt out quickly and completely, as exhaust bubbles and diver movement shakes oxides and other particulate matter loose from every surface inside the wreck. (Not to mention the silt stirred up beneath you from the motion of your fins). Unless a diver has experience following a line and operating in near-zero degree visibility, IMHO that diver has no business penetrating the interiors of any serious wrecks.
So for those reading this thread who have not yet enjoyed much experience inside wrecks...
Some things a basic wreck class should teach you are not to penetrate wrecks PERIOD - without a significant amount of experience and demonstrated skill in diving techniques that -
1. Provide you with superior line handling ability OUTSIDE the wreck, before penetrating inside it (if you intend to run line inside a wreck); and
2. Provide you with bouyancy control abilities far better than most divers demonstrate, to minimize the silting of the wreck interior that will occur as you pass through it (thereby complicating your exit).
Remember also that hatches can close or debris shift so as to block your exit. Teamwork is important inside wrecks. Communications are critical, when signals must be given by the lead diver reaching back between their legs to communicate to the diver behind them in a tight passage. Tools/pry bars can come in handy. There are many environmental parameters that are unique to wreck interiors. Dive teams should discuss these matters at length before penetration.
Aspiring wreck divers need to deeply understand that penetrating wrecks is not to be done lightly. Like cave diving, wreck penetration is notoriously intolerant of error or misjudgement.
Review this site:
www.scubadiving.com/training/lessons/october02.shtml
I agree with you completely, Mike, on one thing:
In my opinion, divers who wish to perform deep wreck penetrations should first take cave classes, to develop line handling and bouyancy control skills that can thereafter be modified for use inside wrecks.
(Actually, Mike, I agree with you on many things. I find your posts to be informative, and don't mean anything above to be challenging to you.)
Safe wreck diving, scubababe.:doctor:
Doc