Am considering the use of 6063 aluminum sq tube to repair/augment the structure of my river boat. Approx 3 yrs ago, I removed the 5 welded on chines that ran the length of the bottom of the boat ( they were mostly crushed & lost their strength ) and covered the bottom with 3/8" UHMW. This has worked very well in order to slowly slip over rocks and to disperse impacts, but the 7' area behind my seat back to the transom has bowed upward ( bending the ribs ) and caused the craft to plane incorrectly. I bent everything back into shape using a bottle jack, post, & the beam in my garage, but I believe the ribs are now fatigued. See attached picture. I'm considering the use of 1.25"x1.25" (1/8") strong-backs welded across the ribs AND to weld 5 additional tubes ( same size ) lengthwise between the transom and seat back across the ribs. Does this seem like a reasonable approach w/ the correct material? I think the lack of longitudinal support across the ribs ( removed chines ) caused a good bit of the problem. Other option is to leave the ribs as they are, and just use longitudinal support w/ 2"x2" box tube. Opinions? You'll notice the rear ribs are interrupted by the jet tunnel. I'm in a rough environment that is beyond the design of this boat ( Lowe 1655TN ), but this fix might get me a few more years if I can miss the big rocks. Any suggestions would be greatly appreciated.