That's good news Rubini, I use 8km & the main problem is the hydrophones, when submerged there are no reports from hydraphone yet on external camera there is a ship above, probably within 2km, but hydraphone reports "Unknown Contact" and this is not in a blind spot, I assume hydraphone should find a known contact way before a visual one!
Sometimes I click on "follow nearest contact" I get the report "No Contact", so I manually listen & shows contact type warship, I then click on "follow nearest contact" and away they go! I'm sure their asleep sometimes!! This may be another problem though!
Thanks.