From the analysis of 1557 calcareous sand grains, a new equation for the computation of particle settling velocity is derived. The proposed expression involves only the dimensionless particle diameter and the Reynolds number, meaning that the estimation of the settling velocity is quick and easy. This formula is compared with expressions available elsewhere and its improved accuracy is demonstrated. When the formula was applied to Hallermeier's database [(1981). Terminal settling velocity of commonly occurring sand grains. Sedimentology 28(6), 859–865], which has been used in previous studies to develop settling velocity equations, it was also found to have the smallest root mean square error. The equation reported in the paper is one of very few expressions specifically developed for calcareous sand.

Marine renewables represent a promising and innovative alternative source for satisfying the energy demands of growing populations while reducing the consumption of fossil fuels. Most technological advancements and energy yield assessments have focused on promoting the use of kinetic energy from tidal streams with flow velocities higher than 2.0 m s⁻¹. However, slower-moving flows from ocean currents are recently explored due to their nearly continuous and unidirectional seasonal flows. In this study, the potential of the Yucatan Current was analysed at nearshore sites over the insular shelf of Cozumel Island in the Mexican Caribbean. Field measurements were undertaken using a vessel-mounted Acoustic Doppler Current Profiler (ADCP) to analyse the spatial distribution of flow velocities, along with Conductivity-temperature-depth (CTD) profiles as well as data gathering of bathymetry and water elevations. Northward directed flow velocities were identified, with increasing velocities just before the end of the strait of the Cozumel Channel, where average velocities in the region of 0.88–1.04 m s⁻¹ were recorded. An estimation of power delivery using horizontal axis turbines was undertaken with Blade Element Momentum theory. It was estimated that nearly 3.2 MW could be supplied to Cozumel Island, amounting to about 10% of its electricity consumption.