Seamen faced both grave dangers and profound uncertainty when considering rebellion. The detailed evidence that we have assembled on dozens of mutinies shows that they resulted from the convergence of long-standing structural grievances among seamen combined with incidental grievances that intensified discontent and focused it on the person of the captain. Rebellious seamen intentionally employed tactics that enhanced coordination and secured the commitment of their shipmates. The occupational culture and social capital of seamen provided them with resources that made mutiny possible.