John, I built a coho with a large circular hatch in the front and a large elliptical hatch in the rear, although the three black webbings announce that there are hatches there the wood blends in nicely as the hatches are flush. Paddled for a few years with a bulkheadless Necky Swallow, and Mariner Express, with both of those I went to rear bulkhead and front float bag after a while. The Mariner has a front one now. BUT, to answer your question: get four! nice large nylon float bags, tie the ends together if possible then stuff them up into the bow and stern. That way you'll be able to inflate them both ennabling them to completely fill up the kayak. And if one has a slow leak you won't have any problems.