yes you are right... for realism sake there would be less one hit wonders.
however here is the problem.
You hit a ship and it steams along at 12 knots under escort... your not catching the damned thing.
and when it sails off into the sunset - even if it sinks 3 hours later outside of visual range
YOU DONT GET CREDIT
factos of life but its a bummer.
If you torpedo a ship and its bow digs 25 feet down into the ocean and it is laden with sea water... the bastard
ought to slow down i would think.
but thats just me thinking again - frequently gets me into trouble.
i use the same tactic with SH5 as i did with previous editions. Send a spread of two fish at anything over 5,000 grt.
this strategy does not seem to do me much good in SH5.