Most African coastal nations prohibit industrial vessels from fishing near their shores; these Inshore Exclusion Zones (IEZs) reserve the richest fishing grounds for artisanal fishers. However, previous research suggests non-compliance by industrial vessels prevents IEZs from benefiting African economies, food security, and fish stocks. Radar data released in 2024 detect industrial vessels without selection, permitting the first estimation of the effects of African IEZs. First, regression discontinuity estimates reveal that 6 of 20 African countries successfully deter industrial fishing. Second, we apply bunching estimators to obtain counterfactual distributions of industrial vessels uncontaminated by spatial spillovers. Third, we capture extensive margin effects by using our bunching estimates to calibrate a discrete choice vessel location model. Back-of-the-envelope bioeconomic calculations suggest that IEZs increase artisanal catch and fish stocks by 6% in the median country where industrial fishing is deterred.