Things that can pierce old fishing gear beside coastal region (8)

I believe the answer is:
bayonets
'things that can pierce' is the definition.
Although both the answer and 'things' are nouns, they are not in the same form of the noun.
'old fishing gear beside coastal region' is the wordplay.
'old' becomes 'o' (abbreviation as in OT - Old Testament).
'fishing gear' becomes 'nets' (I've seen this in another clue).
'beside' means one lot of letters go next to another (I've seen this in other clues).
'coastal region' becomes 'bay' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'o'+'nets'='onets'
'onets' after 'bay' is 'BAYONETS'.
Can you help me to learn more?
(Other definitions for bayonets that I've seen before include "Knives fixed to the ends of rifles" , "Daggers fixed to rifles" .)
