Any clever ideas for cheap flotation? My Jimmy Skiff, a large, open boat, with enough tank flotation to keep her gunwales awash in case of flooding, is about ready for sea trials. Especially the first couple of times out, I would like to fill all the interior space that I'm not personally occupying, with flotation. For a small and narrow boat like a kayak this isn't a problem---plenty of companies will sell you high quality bladders that are convenient to inflate, and fit in the kayak's spaces. But I want different shapes and a lot more volume, and in this case, am willing to trade off sturdy construction for filling a large volume cheaply. Basically, if one of n bags breaks, it's still better than putting to sea with no bags and having a miserable swim to shore, likely sans boat. So, any thoughts on the topic? I can see screwing a set of plastic pad-eyes under the sheer clamps, and having convenient lashing points in the future.