What did the practice of law look like on the high seas? This has been a matter of some discussion among legal historians, with the bulk of the evidence coming from encounters between European ships in the Atlantic and Asia. This article takes a different tack, taking as its starting point a series of contracts copied into the logbook of the early-twentieth century Arab dhow captain (nakhoda) ‘Abdulmajeed Al-Failakawi. Although some of these appear to have been contracts that the nakhoda entered into or witnessed, most were contractual templates that presented formulas for a variety of written obligations between members of the Indian Ocean maritime community. In reading these formulas alongside contracts left behind by Al-Failakawi and other Indian Ocean nakhodas, I reflect on how law circulated by members of an itinerant society of mariners that sought to forge the contours of a commercial world on their ships and across the waters, and weave it through an imperial seascape. I explore how workaday forms of law and legal epistemologies circulated around the maritime marketplaces of the Indian Ocean world, at the margins of a colonial and imperial political economy, through actors who read across different genres of literature, and who moved between the multiple roles of captain, navigator, supercargo, and scribe.