Solo diving is the practice of underwater diving alone without a "dive buddy", particularly with reference to scuba diving, but the term is also applied to freediving. Surface supplied diving and atmospheric suit diving are frequently done by a single diver, but there is a support team on the surface dedicated to the safety of the diver in those cases, and the term is not generally applied. It is a practice which has occurred throughout the history of diving but since the development of formalised recreational diver training, it was deemed by some recreational certification agencies to be unacceptably dangerous, and the practice of buddy diving has been recommended as a means of mitigating the solo diving risks. However buddy diving brings its own set of risks and inconveniences, and some divers elect to dive solo to avoid these problems. Solo diving is practiced for several reasons - some practical, and some philosophical.
In professional scuba diving, solo diving has always been considered an option when it is most appropriate to the operational requirements and the risks have been assessed to be acceptable under the circumstances. However, this usually involves voice or line communications with the surface control point, and a surface standby diver available to go to the assistance of the working diver at very short notice. These options are seldom available to the recreational diver.
The recreational solo diver uses enhanced procedures, skills and equipment to mitigate the risks associated with not having another diver immediately available to assist if something goes wrong. The skills and procedures may be learned by any effective method which provides the appropriate competence, including formal training programmes with associated assessment and certification. Recreational solo diving, once discouraged by most training agencies, has been accepted since the late 1990s by some training agencies for experienced divers who have skills in self-sufficiency and redundant backup equipment.
Solo diving has been defined as a dive planned to be conducted entirely or partly without a buddy. However it is also applied to dives which were intended to be conducted with a buddy, but were continued after buddy separation, and to dives in which there may be other divers present in the immediate vicinity, but none of them are responsible for the safety of the solo diver, or none of them are competent to deal with the consequences of a reasonably foreseeable contingency. It has even been applied to dives where the buddies are insufficiently attentive or close enough to function effectively as a buddy pair, more commonly referred to a "same ocean buddy diving".
The use of the buddy system by scuba divers is intended to improve their chances of avoiding or surviving accidents in or under water by diving together in a close group of two or sometimes three divers, and co-operating with each other, to help or rescue each other in the event of an emergency. This is most effective if both divers are competent in all the relevant skills and are constantly sufficiently aware of the situation to be able to respond in time, which requires both diligence and competence.
Some divers, such as instructors, are effectively acting as self-sufficient divers because they dive with students who may not yet be capable of rescuing them. Others, such as underwater photographers and videographers, dive solo as this allows them a greater opportunity to focus on capturing selected images and not having to rely on buddies to remain close at hand. Even those photographers or videographers who do dive with buddies are often effectively "same ocean" buddies, implying they may be far enough apart physically, or sufficiently focused on their camera-related tasks, to be ineffective as a designated dive buddy—just as if they were diving in the same ocean, but not together. This practice has led to many highly experienced underwater photographers diving solo, since they don't commit to provide timely support to a buddy nor expect such support from a buddy. Underwater hunters also often elect to dive solo in order to focus on their prey.
Solo diving, once considered technical diving and discouraged by most recreational diver certification agencies as more dangerous than buddy diving, is now considered by many experienced divers and some certification agencies to be an acceptable practice for suitably trained, equipped, and competent recreational divers. Rather than relying on the traditional buddy diving safety system, solo divers are self-sufficient and willing to take responsibility for their own safety while diving. The first training agency to offer a Solo Diving certification was Scuba Diving International (SDI) in 1999. In 2011, the Professional Association of Diving Instructors (PADI} started offering a solo specialty called "Self-Reliant Diver", which in many respects (entry requirements, for example) is very similar to the course offered by SDI.
In professional diving, solo diving is normal procedure when one diver is sufficient to perform the required task, particularly on surface supplied equipment, to the extent that it is not even noted as an exception. However, a standby diver is required at the surface or at the bell, and the working diver must be in communication with the supervisor at the surface. Procedures for the dive are based on assessed risk.
Solo divers don't need to work around a buddy's diving schedule.
Some divers will dive in a buddy pair if diving with a known and trusted buddy but otherwise dive solo in preference to being paired up with a potentially unreliable, incompetent, or otherwise dangerous partner. In the United States, the added risk of becoming a respondent in litigation in the event of a diving accident with such a "dangerous buddy" is a motivation to dive alone.
The possible impression that solo divers are unsociable is often wrong. Most solo divers are normally gregarious and want to share their enjoyment of diving with others – they just want to do it when they get to the surface. The solitude they want to enjoy is during the dive. These solo divers take pleasure in this solitude and in the feeling of self-sufficiency for this style of diving, that one is not dependent on others, but is relying solely on one's own skills and capabilities. Finally, there is the sense of freedom, of not being impeded by the need to look after anyone but oneself and therefore being able to achieve one's own goal in the dive without compromising.
There are divers who enjoy specific underwater activities but are unable to find anyone who shares the specific interest sufficiently to dive with them, and where the activity is incompatible with a less than dedicated buddy. The option of simply not diving is not a practical solution, as the diver is then almost permanently prevented from pursuing the interest. Diving with buddies who get bored or tired quickly also does not lead to enhanced enjoyment for either party. When the underwater activity is of interest only to one person, diving solo is the only option that allows the activity to be undertaken.
When photographing or shooting video of shy animals which are easily disturbed, it is more likely to be successful if there is only one diver potentially disturbing the subjects. The disturbance can also be reduced by buddy diving on rebreathers, which cuts down on bubble noise, but at the cost of increased risk due to the inherently higher number of failure modes characteristic of rebreathers. It is not clear which system has the lower overall risk.
There has been much disagreement over the relative safety and merits of solo diving. In 2003, very few statistics existed regarding the impact of solo diving on safety. A 2006 report from the British Sub-Aqua Club (BSAC) concluded that "BSAC currently takes the view that based on evidence from available statistics and risk assessment, the increased risk attendant to allowing planned solo diving is unacceptable". The data underlying the statistics which are used to point to the dangers of solo diving are questionable: for example, divers who end up dying alone but originally had started out as part of a buddy pair are often considered to be "diving solo" in such statistics, but the probability that the separation was a consequence of the triggering incident rather than a cause is not analyzed.
In actuality, studies show that with fatal buddy diving incidents, 57% of deaths happened after the buddy pair had separated from one another during the emergency. Again, these cases could be attributed to failure of the buddy system rather than failure of any solo diving/self sufficient diving system. A further complication in such statistics is that certain more dangerous diving practices (e.g. cave diving) are frequently carried out solo. Therefore, it is a question whether a death in such a dive should be attributed at all to solo diving, instead of just to cave diving. Going back to the figures used by BSAC to categorise solo diving as dangerous it turns out that during 2001–2008 all but one of these "solo diving deaths" were in actuality paired buddy divers that became separated in the fatal incident (75%) or else were divers diving far outside of the limits set by both SDI and PADI for the practice of solo diving (20%) (i.e. actually deep divers, rebreather tech-divers, cave divers). Two further "solo-diving deaths" were not scuba divers at all, but snorkelers.
In almost all circumstances, two highly competent, totally self-sufficient divers diving a specific dive profile as a buddy pair are at lower risk than those same two divers diving exactly the same profile separately, but this raises the question "how often do normal buddy divers both really fit into this particular description?" When considering the risks in solo diving the alternative risks found predominantly in buddy diving need also be considered. The greatest danger to sports divers is inexperience – 60% of all diving fatalities involve divers having less than 20 completed dives. The buddy system itself can be a source of risk – a 2006 survey showed that 52% of buddy divers were at some time actually endangered by a buddy's behavior or actions.
Scuba diving is done in a hostile environment for which humans are not adapted, breathing from a portable and limited capacity life support system. Under these conditions fatality is always a possible outcome, as even simple equipment or procedural problems can be mishandled. In dealing with this reality a number of major concerns about potentially inherent flaws or negative impacts that can exist within the buddy system have been identified. Few, if any, of these problems are defects in the concept of the buddy system, they are problems with the application of the system.
The amount of discipline, effort and attention needed from both divers in a buddy pair, and the even greater input required in a three diver team, is unattractive to a confident diver who has other things to do during a straightforward, low risk, recreational dive, and the system is undermined when any one of the divers fails to put in the effort, putting the burden on the remaining diver who takes the responsibilities more seriously. Familiarity with the environment, and the very low incidence of life threatening accidents is likely to lead to a confidence that there will not be a problem on any given dive, so the divers may pay less attention to good buddy practices, and this may become habitual. This may be exacerbated by the divers being strangers thrown together by chance and the whims of the divemaster, who have no real interest in each other, and whose reasons to dive may be incompatible. Pairing an explorer with a macro photographer will annoy at least one, probably both, if they comply with recommended buddy diving practices. Many nominally buddy dives effectively become solo dives soon after entering the water, with the buddies occasionally checking for the presence of each other and often being beyond direct view of each other. In spite of this, very few of these divers die as a consequence.
Critics of the buddy system state that the proponents project the image of a "totally reliable buddy" that does not generally exist in reality. Some buddies lack skills or experience and some are unfit, and some personality types are outright dangers; these types have been described as "the untrained diver", "the high-flyer", "the falsely confident diver", "the angry diver", "the buddy from hell" and several others. The bad buddy problem is compounded by training that pressurises the diver to "stick with his buddy" at all times, leading to the situation that the bad buddy sets the criteria of how (badly) the dive is carried out. The solo diver avoids this problem altogether.
While there are hazards specifically associated with solo diving, most of these can be planned for and their consequences mitigated by the use of appropriate equipment. In technical diving, where redundancy of critical equipment is standard policy, self-sufficiency is emphasised and taught more extensively than in recreational diving. This philosophy should also be followed by solo divers. A solo diver operating beyond the range for acceptable risk for a controlled emergency swimming ascent needs to carry a second, independent source of suitable breathing gas, which includes a regulator and preferably a submersible pressure gauge. This emergency gas supply typically takes the form of a pony bottle, or for more demanding diving, a twin tank set with the capability of independent operation of each tank. Additional equipment carried may include a backup dive computer, a backup dive light and a backup dive mask. The diver must be familiar with the equipment configuration used and be able to access the equipment easily if it is needed. A solo diver needs to be particularly aware of overall personal fitness and health and the limitations it may impose on their ability to manage an emergency. Finally, the solo diver may dive a more conservative dive plan than he/she might dive with an equally competent buddy diver.
As part of mitigating risks in solo diving the following specific practices have been adopted by SDI for solo diving or are key recommendations by Robert Von Maier—author of the 1991 book Solo Diving: The Art of Underwater Self-Sufficiency:All solo diving is to be done within recreational dive limits (no deep, decompression, penetration, or rebreather dives while solo).
No dives which significantly exceed one’s personal experience limits are to be undertaken while solo
No solo dives are to be undertaken in areas where there are known hazards of entanglement/entrapment
Solo dives will only be undertaken to depths at which the bailout system used carries an acceptable level of risk, the appropriate equipment is carried, and where the relevant bailout procedures have been practiced successfully by the diver.
The solo diver's maximum distance to point of exit (shore, boat) will never exceed a distance that can be easily and comfortably swum at the surface in full scuba gear – and the diver will maintain and exercise his/her navigational practices in solo dives to ensure that this is the case.
The core objective in training to be a solo diver is to become as self-sufficient and self-reliant as possible, to be able to deal with any reasonably foreseeable problems without assistance, and to have the competence, fitness, discipline, skills and equipment that will achieve this result. This requires competence at risk-assessment and the ability to plan dives and select equipment that limit the risks. An additional benefit of these disciplines is that they will improve the safety of buddy diving whenever the competent solo diver pairs up with another diver in a buddy team by reducing the risk of the second diver being exposed to an emergency which they may not be capable of managing. Agencies training solo divers also recommend the self-sufficiency training in their courses for all divers as their diving experience grows, so as to achieve greater safety in all diving—buddy and solo.
Safe solo divers must be self-sufficient, well trained, prepared and practised. They should have a completely redundant set of all life support equipment (e.g. a complete, self-contained backup breathing gas supply). In addition, the responsible solo divers adhere to a very conservative dive profile, both in depth and level of difficulty. Unlike the buddy system, which encourages divers to rely on others in the event of an emergency, solo diving encourages divers to prepare themselves to overcome emergencies by their own means. The divers who engage in solo diving are typically those who are experienced and equipped enough to handle problems themselves. Solo divers must feel totally comfortable and relaxed in doing this sort of diving, and nobody should ever think of doing diving solo if they are not both competent and comfortable in doing so.
Qualifications for formal solo diving training as provided by SDI emphasises the need for experience and maturity in diving. In particular the student prerequisites for the solo diving certification course are:A minimum age of 21 years
A minimum certification of SDI/PADI Advanced Diver (or equivalent)
Proof of a minimum of 100 logged open water dives.
Depending on the country – a certificate of medical fitness
The student must have an acceptable alternative air configuration, redundant gauges and/or computers, SMB and reel, compass, and (depending on training centre) signaling device and line cutting device. During the course tests are conducted on swimming skills and swimming endurance, scuba skills associated with solo diving (e.g. use of redundant air), navigation skills and dive planning skills (including air management).DIWA - (Diving Instructor World Association) - Self-reliant diver, prerequisite - Advanced open-water diver.
SDI - (Scuba Diving International) - Solo diver, prerequisite - SDI Advanced Diver or equivalent
IANTD - (International Association of Nitrox and Technical Divers) - Self-sufficient diver, prerequisite - IANTD Deep Diver or equivalent.
PADI - (Professional Association of Diving Instructors) - Self Reliant Diver