Late to the party but.....
I made one last fall. I drew it up in autocad and had it fabricated from 1/8" aluminum! Fully welded seams lockable latch 10" tall with a 4" double mattress in it. I also reinforced it enough to strap a canoe or whatever else I wanted to the top.
I had a local boat top fitter make the fabric portion with the largest windows he was comfortable fitting.
Have a few little things I will tweak but so far I love it! Definitely an improvement over the soft shell try I had which was great, however, setup tear down was driving me nuts!
I made one last fall. I drew it up in autocad and had it fabricated from 1/8" aluminum! Fully welded seams lockable latch 10" tall with a 4" double mattress in it. I also reinforced it enough to strap a canoe or whatever else I wanted to the top.
I had a local boat top fitter make the fabric portion with the largest windows he was comfortable fitting.
Have a few little things I will tweak but so far I love it! Definitely an improvement over the soft shell try I had which was great, however, setup tear down was driving me nuts!