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The use of anchored fish aggregation devices (FADs) in Indonesian tuna fisheries is facing large challenges. There are two main problems: limited documentation on FAD deployment, and limited compliance by fishers in reporting FADs. Consequently, managing FADs is at present virtually impossible due to inaccurate and inconsistent data that may lead to unsustainable fisheries. In this research, we assess the distribution and densities of FADs in two main areas adjacent to North Sulawesi, Molucca and Celebes Sea based on four data sources. Logbooks of FAD locations from medium purse seine, handline and pole-and-line fishers were used to estimate total numbers and densities; transect surveys were used to check the density estimates; and port authority data were used to compare with the spatial distribution of the logbooks. The latter were not used since they were deemed unreliable. Interviews with fishers gave information on methods of deployment and minimum distances between FADs. We examine the strategies of FAD deployment based on relative influence of various operational and environmental factors. Reconstruction of the total number FADs based on an analysis of the reported and observed minimum distances between FADs (mean and standard deviation 7.2±1.54km, min=3.7km) to remove duplicates ended up with 962 FADs of which 673 in the Molucca Sea and 289 in the Celebes Sea. In particular, the estimate from the Celebes Sea represents most likely only a fraction of the FADs deployed as port authority data show deployment of FADs further from the shore. We show that FAD deployment in North Sulawesi is driven more by operational factors than environmental factors.