During the past five years, Caribbean-West Indian algal ridges have been examined by aerial reconnaissance, surface investigation and coring with C14 dating. In this paper the algal ridges of this area are briefly described and their quantitative distribution by region throughout the area is determined and mapped. Seasonal trade wind constancy and strength is diagrammed and the relationship with algal ridge development examined. Algal ridges appear where the minimum seasonal wind effect index (constancy × strength) exceeds 180 (60% × 3.0 Bf.) and they would dominate reef systems where seasonal minimum wind effect exceeds 320 (80% × 4.0 Bf.). The strong development of algal ridges in Holandes Cays in Panama is anomalously high for that region. It would appear that local shore and reef morphology and orientation can exert considerable control on wave action and can markedly alter local potential for algal ridge development.