This thesis investigates the self-organising of younger volunteers during the 2011 Rena oil spill crisis in Aotearoa/New Zealand. It builds on emerging research that considers the relationships between volunteering and activism and focuses on the ways in which younger volunteers carved out a ‘volunteer-activist’ space for themselves on the edge of the formal crisis responses. The research adopts a case study approach and uses an interpretive lens to investigate three research questions: (1) How was volunteering conceptualised by younger volunteers involved in the Rena crisis?; (2) How did the generational dynamics of younger volunteers affect the various organising responses to the Rena event?; and, (3) How was self-organising conceptualised by younger volunteers involved in the Rena crisis? The data comprised interviews with 53 participants, 38 of whom were classified as younger volunteers (16-29 years of age) and 15 who held positions of authority in the Rena crisis response and who had high levels of engagement with the younger volunteers. By examining the intersections and overlaps of self-organising, younger generations of volunteers, and crisis events through a social constructionist methodology combined with an interpretive lens and reflexive position, the thesis makes several theoretical and practical contributions. At a theoretical level, the thesis challenges traditional crisis management approaches dominated by command and control, formal, or top down organisational structures and arrangements. The thesis demonstrates how, as active members of society, younger volunteers developed alternate forms of participation to strengthen crisis response. Power tensions between younger volunteers and crisis officials were grounded in a deep sense of frustration resulting from negative societal views toward younger generational cohorts and the structural workings of a risk society. By reconciling social and institutional grievances through self-organising, younger volunteers could take advantage of their marginalised position and enact self-reflexive responses in ways that were not readily available to them in everyday life. This sense of empowerment helped younger volunteers navigate the structural uncertainties they faced as they transitioned towards a competitive labour market and also to take greater control of their lives during a crisis. From an Aotearoa/New Zealand, perspective, the thesis also provides insights into how younger Māori participants made sense of and enacted their ‘volunteer’ experience and how this experience was influenced by culturally embedded principles. Importantly, there appeared to be no generational differences between how younger and older Māori participants made sense of their ‘volunteer’ experience. Both groups were driven by collectivist orientations, which highlights the importance of contextualising culture in volunteer sector research. The social constructedness of the media technologies used by participants exposed broader power structures that existed within their generation-specific social worlds. To this end, media multiplexity showed how use of different communication technologies (1) supported the maintenance of relationships between participants and (2) was fundamental to the meaning participants attached to the different forms of technologies. These findings indicate the need to move away from the current literature’s focus on the tools of communication technologies used by younger people during crisis events, towards the meanings that exist behind the use of such technologies as well as the digital relationships fostered among volunteers. This thesis contributes to the scholarship on volunteering and activism by showing how self-organising emerged as an alternative form of activist—or activator—approach to volunteer participation within a crisis response. This approach enabled young volunteer-activators to move beyond their perceived sense of marginalisation and avoid those formal organisational forces that limit their sense of freedom and personal development. The result was an alternative crisis response of self-organised volunteering on the edge of chaos.