The ornamental design for a snap-on tread for boat or recreational vehicle ladder, as shown and described.
FIG. 1 is a perspective view of a snap-on tread for boat or recreational vehicle ladder showing our new design, with unclaimed environment;
FIG. 2 is another perspective view thereof, with the scale or size enlarged as compared to FIG. 1;
FIG. 3 is a side elevational view thereof, with unclaimed environment, and with the scale or size enlarged as compared to FIG. 1;
FIG. 4 is a side elevational view thereof, with the scale or size enlarged as compared to FIG. 1;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
In the drawings, the claimed design is defined by the shaded surfaces; broken lines immediately adjacent shaded surfaces represent boundaries of the claim and form no part thereof. The broken lines showing a portion of the ladder in FIGS. 1 and 3 are included for the purpose of illustrating environment and form no part of the claimed design.