I have found that the best way to make use of the space inside the kayak cockpit is to use waterproof velcro. This product is quite good. I wrapped my water bottles and my hand bilge pump, and laid strips along the cockpit floor in front of the seat. The bottles and the bilge pump now stay in place but are within easy reach, and they do not move around, even when I roll or when there is water in the cockpit. However, it is important to clean all surfaces with acetone and allow them to dry so the velcro will stick well, and be careful to not let any kinks in the sticky side or the water can get inside and loosen the glue. Also, it is probably better to get the 10lb rated, 2 inch wide velcro, rather than the the 15lb rated 1 inch wide version, which wont peel off as easily.
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