Movement time in an underwater environment.

The effect of an underwater environment on the human motor capacity, as measured by Fitts' Law, was determined. Five Ss performed a reciprocal tapping task both on land and underwater. The results showed that movement time (MT) was significantly slower (p < 01) underwater than on land. Underwater the amplitude of the movement was found to have a greater influence on MT than the required precision of the movement. On land the reverse was found to be true with movement precision having a greater influence on MT.