Roy Smith wrote

Boeing just beat out Lockheed for an anti-submarine contract,
and we're going to be replacing P3's with 737's. Can you
really fly a jet at 200 MSL efficiently enough to make this
make sense?

I don't think that the primary mission is ASW any more. And
particularly not "MAD trapping" a submarine at 200'. Seems
as if the new mission is "Ocean Control".
I recall back during the late 60's, our squadron tracked a
Soviet Nuc for a solid month as it maneuvered around Guam and
at no time were the aircraft flown below 24,000'.

Bob Moore
VP-21 P-2V '59-'62
VP-46 P-3B '65-'67