SRTM30plus mask:

    this mask was created by reclassifying the original srtm30plus file into 4 categories by depth class.  the four are:
>-60m = cat 1
-60m to -200m = cat 2
-200m to -2000m = cat 3
<-2000m = cat 4


the cell size for the rater file is 934.478877 in mollwide(wgs_84)

this file was then used to create a mask of the world basins.   all of the basins were aggregated into a single polygon and then converted into a raster using shapegrid in arc with the spatial extent and cell size equal to the above srtm30plus depth class file.

this mask was then used to mask off land for the coral, mangrove, and seagrass layers that were reprojected using the same standards as the basin raster creation.  the values from the orignal srtm30plus reclassification were always used to ensure pixel overlap.