I claim the ornamental design for an underwater weed tarp, as shown and described.
FIG. 1 is a perspective view of an underwater weed tarp, showing my new design;
FIG. 2 is a top plan view thereof;
FIG. 3 is an exploded top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a left-side elevational view thereof, the right-side elevational view being a mirror image thereof;
FIG. 6 is a front elevational view thereof, the rear elevational view being a mirror image thereof; and,
FIG. 7 is a cross-sectional view thereof, taken generally along lines 7-7 of FIG. 4.
The tarp is shown with a symbolic break in its length and width. The appearance of any portion of the article between the break lines forms no part of the claimed design.