The Beckson Thirsty-Mate Hand Pump is specifically made with kayaks and canoes in mind. WE use it on all our programs and courses - it is a great reliable pump that can really move a good volume of water- around half a litre per stroke, so you can pump out up to 30 litres of water in a minute.
The pump is just under 46cm long - you should keep your pump accessible so stowing it under the deck bungees or in the cockpit (use some velcro to keep it in place). The floatation sleeve ensures it will not sink if it does get loose.
The construction of this hand pump is very sturdy - some of our pumps have been going over on our programs for over 6 years with solid use. The heavy-duty plastic construction is reinforced by aluminium - doesn't flex and we've never seen one break.
We recommend having a hand pump on board even if you have an electronic bilge system - you may have a flat battery or a flooded hatch, and they may come in handy to help your paddling buddy.