In low visibility tethering two divers together via a short line (or buddy line) may seem a great idea to avoid separation. A buddy line is generally a short length of line or webbing around 1-2m sometimes with a small central float so it remains out of the way and clips at either end. Each end is clipped to each diver and if you move apart the line tightens and stops you separating. Divers used to good visibility I doubt will have ever come across one or even know about them. Those of us that have dived in really low visibility may consider them an essential item of our dive kit.
As we all know divers are taught to dive in pairs, those purists who believe in the benefits of solo diving should read our post on that. Assuming we want divers to stay in pairs surely stopping separation is paramount? Dive doctrine states that if you lose your buddy you should conduct a quick search then surface to reunite. Whilst this is fine on shallow dives it can mean the end of a deeper dive. Therefore to avoid spoiling your dive, clipping you and your buddy together would seem advisable. There are downsides which divers should consider. The buddy line can cause entanglement of the divers, both of themselves and on underwater obstructions like wrecks and reefs. I will not even start on the dangers of gate clips on buddy lines. Another alternative to a buddy line is for the divers to hold hands. This offers the benefits of touch. You can tell if your buddy has let go, you can’t tell if a buddy line becomes unclipped however unlikely that may be, it is still possible.
Personally I prefer holding hands but it too is not ideal, often to adjust your kit you need to release, one of the pair has to struggle to reach their inflator with the opposite hand if conditions won’t allow letting go. As a pair one could hold on to the other, but should that diver let go the other won’t necessarily instantly know. It seems to be me that there is not a single ideal solution to this problem of avoiding separation in poor conditions. Whichever you choose make sure you discuss it in you pre dive plan along with your separation procedure.
How do you stop separation in low visibility? Do you have an experience of being separated you could share with us?