Abstract.Africa's southernmost coral reefs are situated in Natal Province, South Africa. The Natal coast is exposed to open Ocean swells and episodic storm swell conditions. Benthic communities on these reefs differentiated into three community types: shallow reefs (8–18 m) were dominated by alcyonacean corals and low‐growing, massiveScleractinia;intermediate reefs (18–25 m) were dominated chiefly by branching and tabularScleractiniaof the genusAcropora (A. austera, A. clathrata);deep reefs were not dominated by corals but by sponges. Breakage and recovery experiments indicated that the difference inAcroporadominance between shallow and intermediate sites was caused by breakage in high swell conditions. Survival of experimentally producedA. austerafragments was significantly higher in intermediate than in shallow sites, where higher surge made re‐attachment and regeneration unlikely. Also, colony morphology was adapted to differential surge conditions: colonies on the shallow reefs were smaller with shorter branches, while on intermediate reefs they were much bigger with long, widely spreading branches. Episodic breakage and low fragment survival due to high water‐motion thus excluded branching corals from shallow r
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