Deep ocean water (DOW) is a renewable alternative to the many sustainability challenges that the Caribbean faces today. DOW can provide seawater air conditioning (SWAC) for buildings and greenhouses, provide electricity through an ocean thermal energy conversion plant (OTEC), and provide nutrients for aquaculture and cosmetic industries. However, today the implementation of DOW technologies in the Caribbean is inexistent, and studies about DOW potential in the Caribbean are limited. We present a methodology for estimating the practical potential of a city while considering constraints in ocean currents, temperature, and salinity. We applied the methodology to five cities in the Caribbean and found that the average potential is about 50 m3/s per city, enough to supply more than 100% of a city’s demand for air conditioning and 60% of its demand for electricity. We also estimated the monthly availability of DOW resource, with maximum extraction potentials between December to March, and minimum values between August to October. These estimations serve as input for future feasibility and design studies on DOW technologies in the Caribbean. Given the assumptions, the found potential may be underestimated; thus, the results of this study can be considered as a minimum reference value, complementary to the maximum theoretical potential found in previous studies.