I wrote the Coast Guard about how LxW div by 15 is a formula for overload, their response was tepid--said it was only on 'alternate' formula for those few boats with no capacity plate, meant for box-type hulls in calm conditions, and operator is ultimately responsible for not overloading, etc etc. All true, but pretty passive attitude.
So I think that stupid formula will be around a while. Outdone in stupidity only by Darwin candidates like these* who i supposed have never heard of the formula and couldn't do long division anyway..
*but when they take children down with them it's cruel *and* stupid