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doi:10.3723/ut.31.013 International Journal of the Society for Underwater Technology, Vol 31, No 1, pp 13–19, 2012

Scientific diving techniques in restricted overhead environments

*1,2 3 4 1 Giorgio Caramanna , Pirkko Kekäläinen , Jouni Leinikki and Mercedes Maroto-Valer Pa per 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; 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 , under- techniques to ensure that the research is conducted within 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 diving; for each environ- automated systems can be either complex or impos- ment the specific 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 ; 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 and assessment in 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 ; ‘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 . 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

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Table 1: Example of a table for and . This is to be considered as an example only and should not be used as a reference Environment Hazard Who or what might 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 Divers () 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 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 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

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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 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 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 ate hypothermia can impair the psychomotor capa- well hydrated with warm non-caffeinated drinks is bility of divers (Bowen, 1968; Baddeley et al., 1975; of great importance. The rapid warming of a cold Davis et al., 1975; Ellis, 1982; Coleshaw et al., 1983) diver should also be avoided, since it may induce and thus make them more prone to accidents sickness (Mekjavik et al., 2003). (Parker, 1981). In fact, the possible impact of cold Equipment should be dry, well maintained and in general can also impair the very basic perform- suitable for cold water diving, paying special atten- ance and capability levels divers tasked to produce tion to the regulator’s first stages and the buoyancy accurate scientific results. control device (BCD) inflation, which are more A potential consequence of extreme and pro- susceptible to freezing and free flowing. With the longed periods of low is that diving ever-present threat of a free-flow event from the operations in support of science may have to be breathing regulator, fully independent gas supplies conducted under ice. As with all diving in overhead and breathing regulators should always be carried environments, the most important consideration is with additional consideration of separate bail-out to ensure a safe return to the exit. Most ice attached close to the exit/entry holes. fatalities are caused by the diver getting lost under Care should also be taken to ensure the breathing the ice (Leinikki, 2005). Safe return is best secured gas is dry. Both gas and decompression planning by tethered diver tendering, where the diver is should be adjusted to more conservative values. ­connected to the surface by a line and there is a Breathing from the regulators on the surface should dedicated support team at the surface, normally be avoided. Instead, checks can be conducted in with a stand-by diver. Ice dives are sometimes con- shallow water at the beginning of the dive. This way ducted using cave diving techniques; however, this the risk of freezing caused by formation of ice crystals should not be undertaken unless those involved from the condensed humidity of breathing is strongly are properly trained. In addition, these are tech- reduced. If an open-water dive is conducted in an niques that are unlikely to be recommended for area partially covered with ice, care must be taken most scientific diving operations. so that the divers do not accidentally stray under the Managing a safe under-ice diving operation has ice because of currents or navigational errors. many considerations, but of primary importance is When diving under ice, the lifeline also serves as ensuring that the rope attached to the diver a means of communication between the diver and remains securely fastened so that it cannot be lost. the surface tender, if a full-face mask and hardwire This may entail using ice screws to attach ropes communication system is not used (Fig 1). Secure to the surface. Using lifelines causes the visibility of attachment of the lifeline around the diver beneath the water to become disturbed, and so the need for all the equipment is recommended. All divers lifelines to be secured at the surface is vital. In addi- should be attached to a separate lifeline. tion to the use of secured lines, it is equally impor- As mentioned earlier, a fully equipped standby tant to ensure that both the divers and their tenders diver with rescue skills and an adequate gas source are adequately trained in tethered diver techniques; should be present at all times. Both the diver and under-ice fatalities are higher where there has been the standby diver should have their own tender, thus poor or zero training (Lang and Sayer, 2007). the minimum number of people in an ice diving Because of the added stress from the cold tem- team is four. The standby diver must be launched peratures, the ice cover and diving tethered (if not without delay if the diver under the ice gives an

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environmental conditions. Since flooded caves are a restricted environment, there is no ambient light or direct access to the surface during most of the dive, and typically the diver can only exit from the same entrance point. Therefore, the diver has to rely strongly on the diving equipment for light sources and life support. In order to minimise the consequences of poten- tial failures, a large component in the organisation of the diving equipment is required. At least three different sources of light and two completely independent systems (two cylinders, both with first and second stage regula- Fig 1: In ice diving the diver is connected to the surface by a tors) are the minimum standard equipment (Ward line; donning a full-face mask allows the use of underwater et al., 2008). communicators (Picture courtesy of P Kekäläinen) The environmental conditions that can be dan- gerous for the diving activity are the absence of emergency signal or fails to respond the signals of natural light, limited dimensions of the cave with the tender. occasionally very tight passages and the possibility Although the ice cover forms a stable platform of sudden reduction in visibility caused by the stir- for dive operations, care must always be taken when ring of fine deposits. In high-flow caves, currents can moving on ice as it may give way. Proper equip- be very strong causing an increase in diver fatigue ment, skills for rescue and an ability to recognise and breathing gas consumption. The main hazard suspicious ice are essential. The hole cut through is always the loss of orientation and, therefore, the the ice must simultaneously accommodate two impossibility of returning to the entrance point, divers and be clear of any object that could obstruct which is also usually the sole exit from the cave. the exiting divers. When diving on pack ice, weather and sea level changes need to be monitored, and 2.2.2. Diving methods additional exit holes must be prepared before any The used in cave diving reflect dive. Moving blocks may obstruct the exit, or a diver the special needs of such environments. The breath- may get trapped on the other side of an ice keel. ing gas management must be carefully addressed; a For a thorough review of winter diving proce- standard minimum requirement is the ‘rule of dures, see Leinikki (2005); for more information on thirds’. This rule states that a maximum of one- the specific needs of polar diving, see Lang and Sayer third of the total available breathing gas is to be (2007) and Palozzi et al. (2010), among others. used for the way in, one-third for the way out and the remaining one-third as reserve. It should be 2.2. Cave diving noted that this is a minimum requirement, and Caves most likely represent the best example of sub- ­specific situations may require even stricter man- merged environments that can be studied almost agement, such as one-quarter of the available solely by means of scientific divers (Iliffe and Bowen, breathing gas for the way in, one-quarter for the 2001; Thomas and Bowen, 2001; Oertel and Patzner, way out and the remaining one-half as reserve. 2007), even though highly technological AUVs Owing to such strong limitations, the volume of have been used in deep-cave diving studies in some breathing gas required to support reasonable dive specific situations (Gary et al., 2008). The scientific durations that are suitable or optimal to perform interest in submerged caves is wide, ranging from the required scientific tasks can be very high, and geological and hydrogeological studies (Milanovic, so ‘stage cylinder’ techniques have to be considered. 2007; White, 2007), to biological research (Yager, In such techniques, several cylinders with their own 1981; Iliffe et al., 1984) and the identification of breathing system can be deployed along the cave archaeological relics (Lopez, 2008). Even if the and used by the divers for a step-by-step (or ‘staged’) hazard level is high, correct diving planning and dive (Fig 2). procedures will reduce the overall risk to accepta- Another mandatory technique is the use of a ble levels. safety line during the entire dive. Such line, usually deployed using a reel, is a physical connection 2.2.1. Specific hazards between the diver and the surface outside the cave. The specific hazards attributed to cave diving can The diver must be in contact with the line at all be divided in two categories: equipment failure and times during the dive, and the line should be clearly

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inevitable disturbance of these sediments by the divers during the recovery operation posed a seri- ous safety concern. For these reasons, a specially trained scuba team of the Italian Fire Brigade col- laborated with the scientific divers on the manage- ment of the recovery procedure, thus enhancing the safety of the operations (Fig 3). Another example of scientific diving techniques used in a cave is the geomorphological survey and deployment of a data logger inside a . This spring originates inside the Amaseno cave, which is located at the foothill of the Ausoni Moun- tains in central Italy. Underwater survey techniques were applied to map the 400m long cave. To facili- tate the operations, a permanent line was deployed from the entrance of the cave, and it was moored by means of bolts and nuts fixed inside the cave walls (Fig 4). The line had marks every 10m of a plastic arrow pointing towards the exit; these arrows could be clearly identified by touch even in zero

Fig 2: Multiple cylinders and light sources, together with a reel, are basic gear for cave diving (Picture courtesy of Giancarlo Spaziani) marked with distance and direction to the exit using markers that can be identified even in zero visibility. Irrespective of what types of high-level diving equipment are being used, the diving must be rein- forced with levels of training appropriate to per- form advanced scientific dives in such demanding conditions. A best-case scenario may be where the scientific diver is supported by very experienced cave divers, although science diver must still to be fully trained and proficient for the level of dive per- Fig 3: Identification of inside the Argentarola formed. cave; note the thick layer of fine sediments on the bottom which can reduce the visibility if stirred (Picture courtesy 2.2.3. Research examples of G Caramanna) The collection of speleothems is important for paleoclimatic reconstructions (Hengstum et al., 2010; Vaks et al., 2003). For this reason a was collected inside the marine flooded cave Argen- tarola, along the shore of the homonymous small island just off of the coast of the Argentario prom- ontory (Tuscany, central Italy). The importance of this cave is that it underwent cycles of flooding dur- ing the relative high standing of the sea level. This was recorded by a sequence of marine and conti- nental layers over the stalagmite (Antonioli et al., 2004; Bard et al., 2002). The sampling of the stalagmite required a com- plex system composed of a linked to a fixed line used as track to guide the heavy out- Fig 4: In specific situation the safety line requires tools to be side the cave. The presence of thick layers of very fixed along the cave walls (Picture courtesy of Giancarlo fine sediments on the floor of the cave andthe Spaziani)

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visibility. Extremely low visibility conditions were the results of this research. The scuba experienced sometimes during the return dive, after of the Italian Fire Brigade is acknowledged for their some layers of silt were disturbed during the survey collaboration during the complex recovery of the or after periods of heavy rain and high water fluxes. speleothems inside the Argentarola Cave. Dr Fabrizio Inside the cave, an was dis- Antonioli is acknowledged for inviting one of covered. In order to monitor the hydrologic behav- the authors to participate to the Argentarola Cave iour of the spring, a data logger was deployed in research. Giancarlo Spaziani (Gispa) is acknowl- the lake. The data logger was able to record the edged for the pictures. The authors deeply temperature and the oscillation of the lake sur- appreciate Marco Giordani, Edoardo Malatesta, face every hour. Scientific divers periodically recov- Riccardo Malatesta, Giovanni Ricco, Mauro di ered and re-deployed the instrument for one year. Sebastiano for collaborating in many of the pre- The correlation between rainfall in the area and sented cave dives. the lake oscillation helped in the definition of the hydrological cycle of the spring (Caramanna and Giordani, 2010). References Antonioli F, Bard E, Potter E-K, Silenzi S and Improta S. (2004). 215-ka history of sea-level oscillations from marine 3. Conclusions and continental layers in Argentarola Cave speleothemes The need for scientists to gather data for their (Italy). Global and Planetary Change 43: 57–78. research project may expose them to potentially Auster P. (1997). ROV technologies and utilization by the science community. Marine Technology Society Journal 31: hazardous situations. This is of particular relevance 72–76. to the scientific divers who have strict safety limits Auster P, Stewart L and Sprunk H. (1988). Scientific imag- because of the risks of the underwater operations, ing: problems and for ROVs. Proc. OCEANS ’88. such as limited time and potential levels of stress/ ‘A partnership of Marine Interests’, 1286–1289. fatigue, are higher than that experienced in other Baddeley AD, Cuccaro WJ, Egstrom GH, Weltman G and Willis MA. (1975). Cognitive efficiency of divers working fieldwork activities. in cold water. Human Factors 17: 446–454. Scientific diving in potentially hazardous environ- Bard E, Antonioli F and Silenzi S. (2002). Sea-level during ments requires adopting a thorough risk manage- the penultimate interglacial period based on a submerged ment process with extra equipment and training, as stalagmite from Argentarola Cave (Italy). and Plan- well careful planning of the underwater activities. etary Science Letters 196: 135–146. Once such pre-requisites are satisfied, it can be per- Bovio E, Cecchi D and Baralli F. (2006). Autonomous under water vehicles for scientific and naval operations.Annual formed with enough safety margins as any other Reviews in Control 30: 117–130. activity. Bowen HM. (1968). Diver performance and the effects of It is important to highlight that safety considera- cold. Human Factors 10: 445–464. tions must always take precedence over the main Bowen AD, Yoerger D and Whitcomb L. (2007). Hybrid ROV goals of any scientific diving operation. Dives for 11,000 meter operations. Proceedings of the 2007 Sympo- sium on Underwater Technology and Workshop on Scientific Use should not be performed, or should be terminated, of Submarine Cables and Related Technologies, 206–207. when set safety limits are approached or exceeded. Caramanna G and Giordani M. (2010). Geomorphologic Where the scientific value of conducting research survey and hydrological measures of a by in hazardous environments is considered high, this means of cave diving techniques (Amaseno, Italy). 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