You might find these two websites by the US Government to be of help.
They are observations made by the NOAA buoy located nearest Cozumel.
Although the observations are made near the surface of the water, it shows a graph of how the water temperature varies over the course of the year:
NDBC - View Climatic Summary Plots
and
http://www.ndbc.noaa.gov/data/climatic/42056.txt
They are observations made by the NOAA buoy located nearest Cozumel.
Although the observations are made near the surface of the water, it shows a graph of how the water temperature varies over the course of the year:
NDBC - View Climatic Summary Plots
and
http://www.ndbc.noaa.gov/data/climatic/42056.txt