Growth rates were determined for 95 specimens of Montastrea annularis and 25 samples of 6 other scleractinean species. Samples were collected along five transects at Cane Bay and Salt River submarine canyon on St. Croix, USVI. Montastrea annularis was the fastest-growing species in shallow water (0.4-1.2 cm/yr). Others ranged from 0.15-0.45 cm/yr (maximum), While a general trend of decreasing growth rate with depth (3-40 m) was observed for all corals, rates for Montastrea annularis clustered into two groups: 0.7-0.9 cm/yr in water depths less than 12 m, and 0.20 cm/yr below 18-20 m. The dramatic decrease in growth rate between these depths may reflect a "light compensation depth," below which photosynthetically driven calcification rapidly declines. Analyses suggest water depth, light level, turbidity and sedimentation rate as major controls of coral-growth rate. Slope of the substrate exhibits a secondary but inconsistent control.