doi:10.3723/ut.31.013 International Journal of the Society for Underwater Technology, Vol 31, No 1, pp 13–19, 2012 per Scientific diving techniques in restricted overhead environments *1,2 3 4 1 Giorgio Caramanna , Pirkko Kekäläinen , Jouni Leinikki and Mercedes Maroto-Valer Pa Technical 1Heriot-Watt University, Edinburgh, Scotland, UK 2Italian Association of Scientific Divers (AIOSS), Italy 3University of Helsinki, Finland 4Alleco Ltd, Finland Abstract applications (Auster et al., 1988; Auster, 1997; Scientific diving is an extremely useful tool for supporting Norcross and Mueter, 1999; Sarradin et al., 2002; research in environments with restricted access, where Bovio et al., 2006; Bowen et al., 2007), they cannot remotely operated or autonomous underwater vehicles can- always replace the presence of a scientific diver with not be used. However, these environments tend to be close regard to the quality and reliability of collected data. to the surface and require the application of advanced diving There are also environments, such as caves, under- techniques to ensure that the research is conducted within ice areas, springs or small lakes, in which access can acceptable safety parameters. The two main techniques be restricted and difficult to enter, and where use of discussed are under-ice and cave diving; for each environ- automated systems can be either complex or impos- ment the specific hazards are reviewed and methods for sible to achieve. Some of these restricted environ- mitigating the concomitant risks are detailed. It is concluded ments have related potential hazards for diving that that scientific diving operations in these environments can have to be correctly identified and addressed in be conducted to acceptable risk levels; however, risk man- agement strategies must outline precisely when and where order to guarantee that the underwater research is diving operations are to be prohibited or terminated. undertaken safely. These dangers can be related to environmental conditions such as visibility, the pres- Keywords: scientific diving, diving techniques, hazardous ence of obstructions or polluted waters; or to the spe- environments, restricted overhead environments cific activity performed, such as the use of drilling tools, airlifts or lifting bags. Advisory documents clearly state what kind of tools and methods should 1. Introduction or should not be used by some scientific divers (Euro- Scientific diving has been described as ‘… projects pean Scientific Committee (ESC), 2000). Less clear undertaken in support of scientific research or definitions apply to the environmental limits, which educational instruction” (Health and Safety Exec- are nevertheless of paramount importance for risk utive (HSE), 1997) and/or defined as ‘diving … to identification and management. perform scientific research tasks’ (Occupational Risk management and assessment in diving Safety and Health Administration (OSHA), 1982). requires four main steps: (a) identification of the haz- It can therefore be inferred that, in some cases, div- ard; (b) quantification of its probability;(c) evaluation ing has been accepted by regulating authorities as a of the subsequent possible outcome on the diver; ‘tool’ for scientists that is comparable to any others and (d) identification of a mitigation strategy available to underpin research efforts necessary to (Table 1; Sayer, 2004). For scientific diving, ‘zero’ risk achieve desired scientific targets. procedures will never be realistic as there will always The key advantage of scientific diving is that it be some level of hazard. Therefore, the development allows scientists to study, collect data and conduct of correct assessments and resulting modified proce- experiments in environments which would other- dures that best suit both the environmental condi- wise be out of reach. Even if automated systems, tions and the underwater activities to be performed such as remotely operated vehicles (ROV) or auton- will reduce the identified risks to acceptable levels. omous underwater vehicles (AUV), are widely avail- The present study addresses some environmen- able on the market and can be used for scientific tal conditions that require specific procedures to be applied for scientific diving activities. These * Contact author. E-mail address: [email protected] conditions include, but are not limited to, cold or icy 13 Caramanna et al. Scientific diving techniques in restricted overhead environments Table 1: Example of a risk assessment table for ice diving and cave diving. This is to be considered as an example only and should not be used as a reference Environment Hazard Who or what might Risk control Further risk control be harmed Identify the hazards Identify the individuals or Precautions already Further reasonable actions that could reasonably the groups doing similar taken against the taken in order to mitigate be expected to result work who might be hazard listed the risks that were found in significant harm affected by the activities inadequately controlled Ice diving Cold water Divers (hypothermia) Adequate thermal Stay warm before the dive; (below 5°C) and equipment garments (divers) and limit the dive time; protect (freezing) use of regulators for the regulators from cold water (sealed first contact with ice/snow stage) before the dive Loss of exit direction Divers (potentially fatal) Use of a line connect- Stand-by diver ready for ing the diver with a rescue; use of communi- surface tender cation systems Loss of visibility Divers and instruments Good buoyancy control Avoid being too close to (impossibility of and mastering of the the bottom, or reduce the producing video/ propulsion techniques activity to minimum in photographic records) order to avoid disturbing the sediment Cave diving Failure of the Divers (likely fatal) Use of redundant Mastering of rule of thirds breathing system systems, at least two (or more conservative) in independent gas gas planning and sources experience in the use of stage cylinders Failure in the lighting Divers and scientific Use of at least three Ability to follow the guide system activity independent light line in zero visibility sources Exit direction lost Divers (likely fatal) Mandatory use of guide The safety-reel to be used line with exit direction in case of damage to the and distance from the primary line; knowledge exit marked and of de-tangling techniques recognisable by touch Trapping Divers (potentially fatal) Use of streamlined Proven ability to remove equipment not prone the equipment underwa- to be trapped ter; no metal to metal connections Loss of visibility Divers and instruments Good buoyancy control Avoid being too close to (impossibility of and mastering of the floor and if needed for producing video/ propulsion techniques research needs reduce photographic records) the activity to a minimum to avoid silting-up waters, overhead environments and reduced visibil- scientific diving activities. These cases are not ity. Sometimes more than one of these conditions intended to represent a comprehensive or defini- are present in the same environment, for example, tive overview of all the potentially hazardous situa- in cave or ice diving. This paper addresses specifi- tions for scientific diving in these environments. cally some of the main hazards and mitigation pro- Instead, they relate to some of the specific practices cedures related to scientific endeavours while diving of the authors. under ice or in caves. The discussion is not intended to be exhaustive, nor should it be employed as a 2.1. Cold environments and ice diving form of guidelines or be used in any way as a substi- Extreme cold water and under-ice diving will always tute for specific training and experience. carry levels of risk that are additive to those of basic science-support diving. However, dives in winter conditions are regularly conducted in temperate 2. Case studies and Polar regions for scientific purposes in many The present paper is based on some case studies extreme cold water/weather environments. Cold related to under-ice and cave diving in support of water diving can be executed in a safe manner 14 Vol 31, No 1, 2012 and statistics do not show an increase in incidents accustomed to it), the divers working under ice compared with other forms scientific diving (Sayer should be experienced and have a minimum of et al., 2007). Diving during the ice season may also CMAS 2* (or equivalent qualification) or special have advantages, such as improved visibility and ice diving training. Good buoyancy control is essen- lack of surface vessel traffic. tial for the safe execution of ice dives; tenders should also be competent to properly discharge 2.1.1. Specific hazards their duties. There are two main factors that make ice diving demanding: the cold temperatures and the restricted 2.1.2. Diving methods overhead environment. All cold water diving should be conducted in a dry Cold temperatures alone are a hazard; tempera- suit, and special attention should be paid to the tures below 5°C are an added risk for diving because undergarment, as well as keeping the diver warm of the susceptibility of equipment to freezing and both in and out of the water. It is easy to forget to the risks of hypothermia. Hypothermia per se may drink liquids in a cold environment, but dehydra- not always result in a diver ever approaching a state tion may have a negative influence on non-freezing that could cause fatality. However, mild or moder- cold injuries (Mekjavic et al., 2003), thus keeping