The ornamental design for a watertile, as shown and described.
FIG. 1 is a front perspective view of a water tile according to a first embodiment of the present invention;
FIG. 2 is a left side elevational view of the water tile of FIG. 1, the right-side, top-side, and bottom side elevational views each being a mirror image thereof; and
FIG. 3 is a front elevational view of the water tile of FIG. 1;
FIG. 4 is a front perspective view of a water tile according to a second embodiment of the present invention;
FIG. 5 is a left side elevational view of the water tile of FIG. 4, the right-side, top-side, and bottom side elevational views each being a mirror image thereof; and,
FIG. 6 is a front elevational view of the water tile of FIG. 4.
The broken line showing is included for the purpose of illustrating and forms no part of the claimed design.