decoys - supposed to sound like cavitation?

[Keelbuster]

Decoys in SH3 - from the graphic, it looks like a can from which high pressure gas is escaping. Is this what they were in real life? Like, I'm wondering if they are supposed to sound like an propeller cavitating, as if the sub were diving at flank speed. If this is the case, then why can't we hear them over the hydrophone? Anyone know if they are supposed to sound like cavitation to surface vessels? If so, any way to mod it into SH3?

[GoldenRivet]

it was a chemical device.

the canister contained a chemical called calcium hydride that reacted with sea water and formed a mass of bubbles. (think of a giant alka-seltzer tablet)

not only would the bubbles produce a slight noise that would possibly capture the interest of a hydrophone listener... more importantly, the large cavity of bubbles would reflect active sonar pings as if they were a solid object.

in theory the return would be larger or similar in size to the u-boat. so... the destroyer would either attack the bubbles or would be faced with the decision of which "echo" to attack.

EDIT: to summarize... they were more to fool active sonar pings than to create a noise cavitation.

[Keelbuster]

Interesting - got it. Thx.

[GoldenRivet]

but yes i would think you should be able to hear at least something

[Frank0001]

That's really interesting, I always thought they were noise-producing devices too.
At least, that's what they will become later I believe?