How do insurgents maintain solidarity when faced with increasing costs and dangers? Based on a combination of process tracing and event-history analysis concerning the mass mutinies in the Royal Navy in 1797, this chapter explains why solidarity varied among the ships participating in the Spithead and Nore mutinies. Solidarity, proxied here as the duration of a ship’s company’s adherence to the mutiny, relied on techniques used by the mutiny leadership that increased dependence and imposed control over rank-and-file seamen. In particular, mutiny leaders monitored and sanctioned compliance and exploited informational asymmetries to persuade seamen to stand by the insurgency, even as prospects for its success faded.