Re: Visibilty / Safty or Safty / Visibilty ?

[Jonathan Wallace <jon@whoweb.com>]

>on a 100' dive in my sub you are safely looking out at 2350            
>total pounds...

>from reading many past postings and some recent ones, and from
>viewing some web pages, that many people are getting way to
>far into designing a sub without even doing the basic math
>to get an idea of the pressures and stresses they are dealing      
>with.

I don't necessarily agree that "many" people are designing
inappropriate subs, but on the other hand a good dose of safety
reminding is good to hear from experienced members of the
group.

Quotes of total pressure don't really tell much though, do
they?  As designers aren't we concerned with quantifying
effects of pressure by psi and therefore finding materials
or thickness of material that will resist the pressure of
water on a per square inch basis?