Chris
Try using one of them yellow foam disposable ear plugs as a float.They are very visable and boyant.You just have to thread the line through with a sewing needle.The ear plugs weigh next to nothing and can fit in any where.I've seen some place that by putting a hook in one it can be used to fish for water fowl.I would only do this in a true survival cituation.
Boatman
John