The overwhelming number of accidents encountered on a cave dive will be line derived, most will be caused by a lost line. So it’s all gone wrong? No line not a lot of visibility and the clock is ticking, so let’s not panic.
To do list:
- Stop – don’t make the problem worse by continuing to swim on in the hope that you will encounter the line again.
- Find a stationary object – in most cases you will be near the floor. This will of course carry the risk of making the visibility worse. Although it has the advantage of stopping you moving further from the last point of contact with the line. A roof or wall projection can also be used.
- Keep one hand on the floor and use the other to feel around for the line
- No luck? So now time to deploy the search reel (unless you happen to be carrying a big line reel).
- Using a fixed point of contact rock, wall projection note small weights attached to the search reel are not much use the weight should be at least 1Kg or you will just end up pulling it away from the fixed point.
- You need to make a sweep for the line you should have an idea of how the line is laid:Was it on the floor of the sump or higher in the passage could it be broken?
- Lay out one meter of line and mark a start point if you can and visibility allows.
- Conduct a 360 deg rotation (this is where a start point comes in) using the free hand to feel and probe for the line. Make sure you feel above towards the roof of the sump. In larger passage you may need to move to a higher level to conduct another sweep.
- If this is not successful then progressively layout another 500mm of line. You should eventually recover the line or reach the walls and roof of the sump.
- If you are unlucky enough to not recover the line you now face the decision of moving the fixed point for the search reel. Using the out compass bearing (you will have set before the dive) move a few metres towards this direction. Be cautious of junctions if you swim in to clearer visibility then you may well be heading the wrong way.
- Carry out the search again as in 7 , 8 and 9.
- Now when you find the line you need to know which way is out as you may well have become disorientated. Find the home direction using:
- A well marked line (in and out tags) ignore b. c. d. e. If it is (if you are laying line in a sump or replacing line, it is good practice to tag the line with directional and distance tags).
- An out bearing – this can be problematic in convoluted sumps.
- Depth gauge can give some help as you will know the sump’s profile.
- Familiarity with the sump on the inwards journey (not much use in poor visibility).
- Water flow direction (look around you for scallop marks, note movement of disturbed sediments as a tell tale).
- Note reading instruments can be difficult in poor visibility – use your sinuses/buoyancy to tell you if you are going up or down.
- To stop more confusion when you have found the line you should have put out tags on junctions (on the inward journey) this will stop more concern of “is this the right way” this should be standard practice! Unless Permanent out tags are fitted.
- While all this is going on keep checking gas reserves and keep following the line recovery procedure. At some stage you will reach a point a more drastic action is needed (course of last recourse). Using the out compass bearing head towards this direction as stated before beware of clear water as this could well be the wrong way.
- If gas reserves are low it is worth looking for an airbell better to sit it out and wait for a search team than push on without enough gas to get out.
Alternate strategies – if you are in the sump with someone else behind you it might be worth holding position until they arrive (following the line) and use them as a lighthouse to re-locate the line.
Look at your compass and depth gauge during the dive – consult any surveys available beforehand. The combination of the two (in addition to noting passage features) will tell you where you are in the sump and may be useful in an emergency. It will also be a less stressful dive as you will know where you are.
If you don’t have a search reel (very naughty) then more creative methods can be used – e.g. follow a feature in the passage in one direction and then another in order to have a route back to you reference point. Follow a line along the wall for example.
Above all try to stay calm and don’t panic. The third’s rule means that you will only be at your most vulnerable at your turnaround point. If early or late in the dive you will have a considerable safety margin.
A M Ward and D M Price October 2011