[fatlazyless]

I have a very old aluminum dock that came with my cottage, and it looks like it was made in the 1950's or 1940's and is still very usable despite having been crunched once by a moving ice sheet. I just keep fixing it and fixing it and fixing it ...... sort of like driving a 1952 Chevy Bel Air in Havana, Cuba, for your one and only car. Is about 5' x 40'.

If I were to replace it, I'd look at the 'dock in a box' items at Walmart.com, where you get a 4x8', or 5x10' aluminum dock section with legs, and it includes the measurements for the removable decking which can be any of pt lumber, redwood, mahogany, or trex plastic. You purchase the materials for the decking at the local lumber yard, and build it yourself. Probably, would go with 1 1/4" pressure treated lumber that's removable from the aluminum frame, and stain it with grey latex stain, and re-stain it as needed, years later.

Or, try googling 'aluminum do-it-yourself boat dock kits.'

Having the heavy pt-lumber decking removable from each aluminum section in two decking sections makes it all be light weight enough for easier installation /removal.

After looking at the 'dock in a box' items, maybe you want to check out the 'hot tub in a box' made by Intex.