The ornamental design for a watercraftbow, as shown and described.
FIG. 1 is a perspective view of a watercraft bow;
FIG. 2 is a front view of the watercraft bow of FIG. 1;
FIG. 3 is a back view of the watercraft bow of FIG. 1;
FIG. 4 is a side view of the watercraft bow of FIG. 1;
FIG. 5 is a top view of the watercraft bow of FIG. 1; and,
FIG. 6 is a bottom view of the watercraft bow of FIG. 1.
The broken lines immediately adjacent the shaded areas represent the bounds of the claim and all other broken lines represent unclaimed portions of the design. None of the broken lines form a part of the claimed design.