Have a 1984 First 345 Beneteau. It has original water bladders by Nauta. 22 inches wide, 84 inches long, tapered at bow to 11 inches wide. When inflated 16 inches diameter. Both bladders need to be replaced. Told by Beneteau that they no longer make the bladders. Research indicates that no one makes custom bladders any longer. Any suggestions? Thanks.