The ornamental design for a waterpipe, as shown and described.
FIG. 1 is a perspective view showing the top, back, and left sides of a water pipe showing the new design;
FIG. 2 is a perspective view showing the top, right, and front sides of a water pipe showing the new design;
FIG. 3 is a top side elevation view thereof;
FIG. 4 is a bottom side elevation view thereof;
FIG. 5 is a left side elevation view thereof;
FIG. 6 is a right side elevation view thereof;
FIG. 7 is a front side elevation view thereof; and,
FIG. 8 is a back side elevation view thereof.
The evenly spaced dashed broken line shown in the figures illustrate portions of the water pipe that form no part of the claim. The dot-dash-dash-dot broken lines represent the boundaries of the claim and form no part thereof.