WordNet sense 1 (aimlessly drifting):

aimless, rudderless, directionless, planless, undirected

WordNet sense 2 (not evidencing any purpose or goal):

purposeless

WordNet sense 3 (covered with water):

awash, flooded, inundated, overflowing

WordNet sense 4 (containing as much or as many as is possible or normal):

full

WordNet sense 5 (borne up by or suspended in a liquid):

floating

WordNet sense 6 (afloat on the surface of a body of water):

adrift