I need a swim platform for my 29' Warlock world class, but i have a few ideas id like to do to make it different then a lot of ones i see, but i also want it a little smaller then most of the 2" diameter tube ones that stick out 25", so i think I'd like to just build it myself. I have access to all the welders and benders I'll need, my question is on the material itself. What grade of Aluminum should i use? And what wall diameter would be best (as far as being a good comprimise of strength, weight, bendability, ect). I'll be mounting a stainless ladder underneath it when finished. Thanks

Ayuh,.... I built my bimini outa mostly 1, 1/2" aluminum conduit,.....

It's fairly easy to find, easy to work with, 'n easier to bend,...

I'd do the same for a swim platform,...
1, 1/2" perimeter bar, probably 1" cross bars,...
Probably make the ladder at the same time, outa the same stuff,...