This article explores the experience of the surf therapy sector developing a coalition using the collective impact framework. Several dozen surf therapy programs and sector supporters now meet annually to discuss progress and collaborate on shared sector goals after years of programs working independently and even viewing one another as competitors. Key participants found collective impact worked in encouraging shared leadership, common agenda, reinforcing activities, and continuous communication. However, participants found challenges with collective impact in the approach feeling top-down, difficultly agreeing on a common agenda and shared measures, and uneven contribution and follow-through from programs. Additional challenges included limited opportunities for program participants to contribute to the coalition building, lack of a social justice orientation, and lack of backbone organization funding. Recommendations for sectors using coalition building include considering funding and previous experience building coalitions, finding humble and bold leaders, getting the timing right, being focused and realistic with targets, and streamlining decision making.