Sonar Blindness Re: FT-Subs?

> At 11:38 AM -0400 7/28/01, Richard and Emily Bell wrote:
Escorts can
> detect subs passively at a range of six times the applied thrust (less

This was because as the ship got closer to the sub (driving directly at it to
pass over for a depth charge salvo off the fantail) the sub
passed out of the sweep of the ASDIC/Sonar 'beam'. The subs could
dash out of the way at the last instant if good.

Hedgehogs, K and Y guns and 2 ship tactics helped to counter this blind spot
below the ship.