Universal search programs catching American naval vessels (1-5)
I believe the answer is:
u-boats
'vessels' is the definition.
(U-boat is an example)
'universal search programs catching american naval' is the wordplay.
I cannot quite see how this works, but
'universal' could be 'u' (film certificate) and 'u' is found in the answer.
'american' could be 'boa' (I have seen 'native American' mean 'boa' so perhaps 'american' could also mean 'boa') and 'boa' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for u-boats that I've seen before include "German submarines of second World War" , "German submarines in WW2" , "German subs" , "Submersible warships" , "Submersible ships of WW2" .)