Please don't give the knee jerk reply, yes of course it's the law.

Hear me out.

One time a few years back I was renting a small tractor.

I went to cross the chains on the trailer when hooking it up and the
rental guy said.

Don't let the state cop see you do that or you'll be fined.

The reasoning is, if you cross them and the ball fails you can
continue driving merrily down the road completely unaware that it is
off the hitch because the chains are holding it up.

It's better for the failure to make a lot of noise to alert the driver
to STOP immediately.

This logic made perfect sense and I have not crossed them since.

Now taking a new required boating test it says cross the chains. Also
doing google searches everyone says cross them because that seems
logical to prevent damage to the trailer hitch. But who gives a crap
about the hitch. What is the safest thing to do to minmize further
havoc and to me it makes sense to not cross them.

It's sort of backwards logic, like it's required to have an electrical
outlet installed near a new pool installation. Because otherwise
people will use an extention cord that could end up in the pool, which
is worse than having a properly ground faulted outlet nearby for the
boombox or weed whacker.

So I wonder if over the years people have screwed this choice up of
crossing and not crossing trailer chains.