The ornamental design for a waterbottle, as shown and described.
FIG. 1 is an isometric view of a water bottle according to the present invention.
FIG. 2 is a front elevation view thereof.
FIG. 3 is a right-side view thereof.
FIG. 4 is a rear elevation view thereof.
FIG. 5 is a left-side elevation view thereof.
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken dash lines in the figures are for illustrative purposes only and represent non-claimed environmental subject matter. Neither the portions of the invention shown in broken dash line nor the broken dash lines themselves form any part of the claimed invention.