Not trying to scare you but the thing about tempered glass, in my experience, which is considerable with clear sheet materials, is that it just isn't all that hard to break. I always felt that the main advantage in most uses is that it doesn't sliver and is therefore less dangerous if broken. Most times when people want glass to be really tough, it is laminated. Not because it won't break but because it stays together after it breaks.
3M makes blast proof laminate that you can apply to glass yourself that will not give up even when the glass it is applied to is in tiny pieces. I think it is the same stuff between laminated sheets, though the glass people would never tell me for sure. If I had glass ports or lights on a boat, I would definitely consider the laminate as and addition. Alternatively, you can buy laminated, tempered glass and be more or less bullet (certainly wave) proof.