How do I hunt effectively for merchants?

[Carda1972]

Hello Subsim,

Today was my first 'mission' in the campaign so I'm still kinda new to SH5. I went to the patrol area and started hunting for some merchants (On surface -> Speed setting 4 -> Time to 512x). I guess this wasn't the best way, because at 10PM (22:00) I 'ran' into a small convoy of 4 merchants which my crew detected at 1900m distance , much too close to my opinion. Before I could turn they closed in to 1650m and I think they detected me, because I noticed they changed to that zig-zag pattern.

Now I was thinking: At the surface with this speed, the hydrophone doesn't help my crew find anything.

What is a good strategy to find merchants in SH5? I heard the hydrophone can hear traffic to 30km in distance but does SH5 render traffic this far from the sub so this feature can be used? Is the hydrophone controller guy really able to hear traffic at this distance AND REPORT THEM to me? Should I submerge to 20m each hour and do a full sweep myself instead?

What works best for you and for SH5?

Thank you so much, I'm really starting to love this game,
Carda

edit:

Upgraded hydrophone guy to level5 in listening and after one hour dived to 20m to do a manual sweep myself. Heard a contact at bearing 30degrees BUT the hydrophonist guy doesnt report the target... Not a single message like 'hydrophone contact at bearing 30 degrees'.... am I doing something wrong here?

Thanks again