Spatial information is limited for artisanal ﬁsheries management and almost entirely absent for migrant ﬁshers. Here, we addressed this data gap for East African migrant ﬁshers via participatory mapping methods. We worked with 14 migrant ﬁshing vessels operating from four ﬁsh landing sites in Kenya. We monitored individual vessels using GPS tracking to produce ﬁshing ground intensity maps. We then generated ﬁshing preference maps via focus group discussions. The ﬁshing intensity maps provided high-resolution spatial information on ﬁshing activities, whereas the ﬁshing preference maps identiﬁed preferred ﬁshing grounds. These two techniques generally showed high agreement. By further integrating these two ﬁsher coproduced maps with supplemental vessel logbook data, it is clear that any spatial management measures would most aﬀect migrant ﬁshers using ringnets, hook and line, and cast nets gear. Our successful application of low-technology participatory mapping techniques to provide geospatial ﬁsheries data have broad application to data poor ﬁsheries worldwide.