I hope I never have to use it, but it's far better to have it and not need it. I tried it by holding it over the side of the kayak. I wish the discharge was on the down stroke instead of the upstroke but it's still a great pump. I bought it after finding myself on a very long pond, and the wind suddenly whipping up causing six-inch waves with little white caps splashing over the bow of my kayak. It was a long haul, paddling against the wind, back to the launch ramp, and I had no pump at the time. This is why I bought one. It only takes a couple of gallons of water to start the kayak sinking lower in the water, and the lower it goes, the more water enters. It wouldn't take long, like that, to find one's self in the water instead of the kayak. I'd say the pump is essential equipment, especially in a sit-in kayak like mine.