The ornamental design for a safetydevice for swimmingpools, as shown and described.
FIG. 1 is a perspective view of the top, front and right side view of a
safety device for swimming pools showing my new design, the rear view
being a mirror image of that shown, and portions of the cord shown broken
away indicate indeterminate length and for convenience of illustration;
and,
FIG. 2 is a right end view of FIG. 1 with the left end view being a mirror
image thereof.