Make sure that you have a clean, decal free, 5”x13” smooth spot near the waterline at the back of the boat. Then press in on the two blue levers before rotating them down into the locked position. This fully exhausts the air and water out of the cups ensuring maximum grip.
If you store your boat in the water, you may also need to clean the area where DELTA will attach periodically. A 3M blue scratch-free scrubber works well to remove the waterline algae that sometimes accumulates by the end of summer. Wax and polishes do not affect the gripping power of the suction cups.