capt. chairs vs back to back

[FXRSCOTTY]

The deck under my capt, chairs in the Sceptre is a little soft. The chairs wobble. I have T nutted them but they keep getting loose. Should I replace with back to backs or is there an easy way to correct this? The chairs are too tall and I will be cutting at least 4 inches off posts if I keep them. The only time i sit is at trolling speed. What do you guys think? Scotty.