Imagine we are doing a production aluminum catamaran and we want our own team to be able
to inspect the welds the shipyard has made.  
I think this is called non-destructive testing (NDT).

Some types:
1) Visual Testing (VT)
2) Leak testing - with air pressure or by filling with water
3) Ultrasonic testing (UT)  
4) Phased Array UT (PAUT) 
5) Dye penetrant testing (PT)
6) Eddy Current (ET)
7) Radiographic Testing, X-ray, gamma

For each of these:
   1) What does the equipment cost?
   2) How much training does it take? (days and dollars)
   3) What types of defects can it detect?
   4) What are some of the top sources

The radiographic has safety issues, can we avoid it altogether?  Can we test well enough without it?

How long do you think it will be before there is a humanoid robot that can do inspections
of welds on an aluminum catamaran?

It seems clear there should be an inspection after the welding is done but I also wonder if this is
something that should be done every few years or if it is just after manufacturing.