getDepth(latitude, longitude)

DEPTH = GETDEPTH(LATITUDE, LONGITUDE) estimates the seabed depth DEPTH at specified coordinate(s). LATITUDE and LONGITUDE coordinates can either be numeric arrays specifying decimal degrees or cell arrays of strings specifying degrees, minutes, and seconds or GPS degrees. DEPTH is returned in meters, where negative values correspond to depths below sea level.
If LATITUDE and LONGITUDE are cell arrays of strings, the hemisphere designator (N/S/E/W) must prepend the location (e.g. 'N 37 23 30') and all values must be separated by spaces.
This function uses the Marine Geoscience Data System website to obtain seabed estimates from their Global Multi-Resolution Topography (GMRT) dataset. Thus, an Internet connection is required.
Examples:

getDepth(32.930667, -117.3175)
getDepth('N 32 55 50', 'W 117 19 3')
getDepth('N 32 55.84', 'W 117 19.05')
getDepth([33.52 35.14], [-119.88 -123.35])
getDepth({'N 33 31.2' 'N 35 8.4'}, {'W 119 52.8' 'W 123 21.0'})
getDepth({'N 33 31 12' 'N 35 8 24'}, {'W 119 52 48' 'W 123 21 0'})