In the last decade, collective coordination in sports has been studied from the perspectives of three main theoretical approaches: the social-cognitive approach, the ecological dynamics approach, and the enactive approach (Araujo and Bourbousson, 2016). Most of the studies referring to these approaches mainly focused on cognitive, behavioral and phenomenological dimensions of the coordination between teammates. By doing so, they underestimated the role of the relations between the system composed of the teammates interacting with a shared sport equipment, and the natural environment of that system. In the present study, we referred to sport equipment as the equipment required for engaging in a sport. In contrast, we referred to the natural environment as the surrounding environment of the athletes-sport equipment system. We referred to "shared" sport equipment when both athletes' bodies are in contact with a same piece of equipment. For example, we considered a boat as a shared sport equipment in sailing, whereas we would not consider a racket as a shared sport equipment in double tennis.
Recently, some authors encouraged the consideration of the role of sport equipment, and more particularly when this equipment is shared and "sensible" to the athletes activity (i.e., when each athlete's activity affects the shared sport equipment) (Millar et al., 2013; R'Kiouak et al., 2016). This is for example the case of a rowing boat that is highly affected by every movements of each rower. In contrast, a soccer field has a limited sensibility to athletes' activity, even though the grass keeps traces of some of the players actions. The aim of the present study was to pursue the exploration of the role of the shared sport equipment in the production of collective coordination in sports. We focused specifically on the study of collective coordination within crews of flying multihull sailboats (i.e., multihulls equipped with hydrofoils). This choice was guided by the fact that the flying boat is a shared sport equipment highly sensible to the crew members movements. Furthermore, wind shifts and water movements also affect speed and balance of the flying boat, constantly challenging the flight. Flying boats can be distinguished from non-flying boats by the capacity of reaching and maintaining a precarious dynamic equilibrium with only a set of appendages (the hydrofoils) remaining in contact with the water (Binns et al., 2017; Heppel, 2015). Because of these singular characteristics of flying multihulls, this situation is particularly relevant to explore interactions between crew members and their shared sport equipment (i.e., the boat equipped with hydrofoils). Indeed, the dynamic behavior of the boat under changing physical environmental constraints requires ongoing individual and collective adjustments of the crew members to maintain flight.
The role of the sport equipment in the explanations of collective coordination in sports
In the domain of sport psychology, the role attributed to sport equipment in collective coordination varies depending on the theoretical assumptions that grounded the studies.
From the social-cognitive perspective, the performance of a team relies on the capacity of each team member to know what his or her teammates are going to do and when they will do it (Eccles and Tenenbaum, 2004). Researchers have studied shared mental models (Cannon-Bowers et al., 1993; Eccles and Tenenbaum, 2004) and team situation awareness (Cooke et al., 2004). In these approaches, collective coordination relies on each team members knowledge: research on shared mental model primarily focuses on long term team knowledge and research on team situation awareness focuses more on the dynamic aspect of the team's situational knowledge (Cooke et al., 2004). A lack of shared knowledge could lead to weak coordination and reduce the team's ability to adapt to changing environmental demands (Cannon-Bowers et al., 1993). For example, Lausic et al., (2009) speculated in a study on female tennis double teams that winning teams could be more attuned to court conditions, such as wind and the speed of the court surface. In this social-cognitive approach, the environment (including sport equipment) is thus essentially considered as an "inert" source of perceptual cues, that can be shared (or not) by the teammates to coordinate one another.
Compared to the previous perspective, the ecological dynamics framework emphasizes more on the role played by the environment (including sport equipment) in collective coordination. This framework articulates key concepts from ecological psychology and non-linear dynamical system theory (Seifert and Davids, 2017). On the one hand, the ecological psychology approach highlights on the continuous coupling of perception and action for individuals. Therefore, in this approach perception is not necessarily mediated by prior knowledge about the world but there is a direct perception, for each individual, of opportunities for action offered by the environment, i.e., affordances (Gibson, 1979). On the other hand, non-linear dynamical system theory provides a conceptual framework for studying self-organization of complex systems and the emergence of coordination tendencies at individual and collective levels (Seifert and Davids, 2017). Studying cooperative social actions, Marsh, Richardson and Schmidt (2009) consider it valid "to conceptualize two people coming together in a 'joint perception-action system' as a new entity with new abilities" (Marsh et al., 2009, p.326). Within this approach, investigations in rowing (Seifert et al., 2017) showed that the behavior of the boat (i.e., changes of the boat velocity) were associated with destabilized collective coordination. Furthermore, the understanding of collective coordination in sports within this approach, takes into consideration not only what the other team members think or know, but also the perception of other actors' affordances. This includes the perception of what actions another actor can provide under a given set of environmental conditions (i.e., affordances for others) and what actions of another actor afford a perceiver (i.e., affordances of others). For example, a ball carrier who perceives a closing gap between defenders, or between a defender and the sideline, is actually detecting a negative affordance for going forward (Silva et al., 2013). Other studies in rowing showed an original way to perform a collective task, highlighting the mediating role of the shared sport equipment in collective coordination. A qualitative study of expert rowers (Millar et al., 2013) showed that collective coordination in pair rowing boats is supported by the perception of the boat's behavior. They have called this type of coordination "extra-personal coordination". These results point out that collective coordination is linked to situational constraints and highlight the role of the sport equipment (including shared sport equipment) in triggering opportunities for joint action. Thus, from the ecological dynamics' perspective, shared sport equipment plays an active role by circumscribing the opportunities for individual and collective actions.
More recently, R'Kiouak et al. (2016) studied the mediation of a shared sport equipment in crew coordination between rowers, beyond the study of Millar et al. (2013). This research was conducted within the "course of action" framework, rooted in an enactive approach of cognition.
This approach considers cognition as an enacted property of the history of the structural coupling of an autonomous organism with its environment (Maturana and Varela 1987). This coupling is asymmetrical in the sense that the autonomous organism regulates its interactions with the world, transforming the world into a place of salience, meaning and value through a "sense-making" activity (Thompson and Stapleton, 2009). In this approach, human coordination emerges from interactions between actors, these interactions affecting individual sense making activity (De Jaegher and Di Paolo, 2007). The enactive approach differs from the previous one by putting emphasis on the study of lived subjective experience to understand human activity (Shear and Varela, 1999). The results showed that rowers were in synch for a large part of the race without simultaneously having a salient, meaningful experience of their joint actions' effectiveness. The authors put emphasis on the mediation of team's coordination by the shared sport equipment (i.e., "extra-personal" regulation processes) referring to the concept of stigmergy (Susi, 2016). This concept was introduced to explain collective coordination observed in groups of social insects: each insect affects the behavior of other insects by indirect communication through the use of material artifacts (Susi, 2016). R'Kiouak et al. (2016) suggested that, despite major differences between the activities of rowers and social insects, in the rowing situation the boat plays a mediating role, as its behavior is affected by each rower's activities.
In the present study, the flying boat presents similarities with a rowing boat as both are highly affected by each crew members' activities. However, on a flying boat the respective activities of each crew member, are very different from those of rowers, depending to their own specific roles on the boat. The constraints of their collective task require a reciprocal interdependence (Saavedra et al., 1993) between helmsman and crew, who regulate specific controls of the boat. Moreover, the flying boat is also highly affected by its natural environment that contributes to its propulsion and dynamic balance, whereas in rowing the natural environment has a less functional role.
Theoretical framework and research purpose
The study was conducted within the course of action theoretical and methodological framework (Theureau, 2003, 2006), that is particularly...