Is it legal to build and operate a pontoon boat with no rails/walls?

We are currently rebuilding a pontoon from the floats up. We are debating whether or not to include railing or walls. We can't find any laws/regulations regarding the requirements of this. I always thought they were required, but my partner disagrees. Thanks.|||If it is used to carry passengers then no guard rails could be interpreted as an unsafe water craft if it is used an registered as a work boat then a certificate of allowance can be issued if the original railings are beyond repair consider using speed rail products as it utilizes 1.5" pipe %26amp; boltable feet, tees, corner tees, and cross tees, at a reasonable price not very attractive but sturdy.