RE: A123 batteries fo a sailboat?
I saved the plastic box that my Hitech servo came in. I cut a small hole in the top for the power leads to exit. The 2 cell A123 fits nicely inside and will keep any water in the bilge from splashing into the batteries. I have a rectangular hatch that is large enough to slip the box through, into a cradle to keep it from sliding around. The hatch is taped to seal it.