The ornamental design for dock securement for boats, as shown and described.
FIG. 1 is a left front perspective view of the dock securement for boats, showing my new design;
FIG. 2 is a top view thereof;
FIG. 3 is an front end view thereof, the back end being a mirror image thereof;
FIG. 4 is a cross-sectional view taken across lines 4-4 of FIG. 2 to show the latch recess thereof;
FIG. 5 is a cross sectional view thereof taken across lines 5-5 of FIG. 2 to show the latch recess and the hole for a tethering rope; and,
FIG. 6 is a left side view thereof, the right side being a mirror image thereof.
The broken lines in the FIGURES representing the dock, rope and screw heads form no part of the claimed design. The bottom of the dock securement constitutes no part of my design.