Sonobuoys vs biological
 

Training on P-3, Played mission "Victors three" by TLAM strike, P-3 has to locate 3 Victor subs in K's of sq nm area.

Got hot buy, and wasted lots of VLAD's to narrow search area for, apparently, loud but no freq contact. When decided to change my buys loud out, replay showed I was chasing biological, duh!

I wonder, how biological can be distinguished with sonobuoys? Any tips?

Unless I'm missing something, you answered it yourself! Biologics have no frequency data, just loud broadband.

Also, because biologics tend to be so loud, you can hear them from really far away. Anything that's really far away is going to look like it's staying still (bearing constant - all LOBs parallel in TMA, not applicable to sonobuoys, I know). That is also a dead giveaway because any ship that loud is going to be somewhat close, even if it's heading more or less right towards/away from you, its bearing is going to be changing.

Well, there was no broadband from sonobuoys too, only hot (red) buoy's, which can mean anything - sub or surface contact.
I didnt knew, Does really buoys transferring sounds, or You talking about ship acoustics?

At this moment seems like range is only helping to distinguish Biologicals, but that means You gonna need waste some buoys just to confirm its not biological and dropping them +- 50nm i guess from hot buoy.

You can look at the output of the buoys. Did you not know that? But, yes, in a mission with biologics, all buoys will be forever "hot", therefore, eliminating your ability to tell if something is there.

You don't need to drop anymore buoys than you normally would to get a triangulation. Two, preferably three, sonobuoys in 5-10 nm line is sufficient to look at and say "oh, that intersection is way out there! most likely that is a biologic".