Nested catch and throw do not seem to work properly

Ok, thanks!
I was wondering.
Anyway, I am using "massively" try-catch-throw to speed up some gps related software. Basically, nmea protocol provides figures much more often than text.
So I use try as a way to make it faster in most cases, which means numbers, handling exceptions, strings, almost at no extra costs.
Anyway, that's to be added in the list.