Destroyer's detection circles
 

I was submerged and maneuvering between two destroyers recently and it reminded me of a question I've been meaning to ask. Those various circular lines around the destroyer on the nav map; I know about the angle projected out from behind the escort, about 45 degrees, ("behind the escort's baffles") where their sound detection is lost, but what's the significance of the others?
1) The spade-like projection right in front of the ship; what's it signify?
2) The smaller, closer circle around the ship....?
3) The larger, outer circle around the ship...?
Thanks for the help!

I believe it is the detection zone of their ASDIC

My guess would be visual range


My guess would be hearing range.

Anyone else?

My guess would be (from largest to smallest): Passive hydrophone, visual spotting, active pings. Not totally sure.

At some point they'll start using radar too; so that may be one of them.

I haven't played stock SH3 in so long, I forgot it even had such map aides.

The outer is the visual range; the inner one with the triangle at the stern of the warship denotes its passive acoustic equipment.

The visual circle is a guideline for "normal conditions," so sea state, fog, day/night, affect when/if the escort will actually see you visually.

In the same way, in the acoustic circle, your silence, your depth and your angle in relation to the escort will determine your acoustical "visibility."

Whether you play stock or GWX, it is worth reading the GWX Manual Appendix B thoroughly to understand how things work within the acoustic circle, as they change over the course of the war.

When the escort is equiped with radar, there will be another circle as well.

Also, the circles will change size depending on if the escort is equipped with better sonar/radar.

Kinda unrealistic methinks.
Is there any way to make them disappear? :06:

:)