Not sure about the "standards" aspect, but two things. Firstly, a toughend glass is equal to ten times it's thickness in standard glass. So a 10mm(3/8) armourd glass is equall to standard glass 100mm(4") thick.
However, a cubic meter of water
weighs in at 1tonne. Now put some speed behind it, and the impact on a window is huge. Often it is not the glass it'self that breaks (although it can and does happen) it is the frame that holds the glass in that can simply give way.
Most ocean cruisers will or should have storm shutters for large windows. These can be simple ply panels
that bolt over the window and take the impact.
It should also be noted, that there should be emergency panels
carried for the event that a window does blow. There should be at least one emergency
shutter for every window shape in the boat
. The emergency shutters are usually two pieces. An inner and outer with a through bolt so as they clamp together.