I'm new, presentation and a question about Spot contacts

Hi guys!

Well I'm new posting here but I have read quite a few posts. And I'm not new to Silent Hunter, I've been playing since silent hunter II which I still remembered as the best of all.

My question is about Spot contacts. Some times when I'm travelling at 512 or more TC, and suddenly it solws to x8 TC or x1TC, but nobody says nothing. And when I checked the sea I can see on the Horizon a ship, but nobody tells me anything.

Is this a bug?, or That is how it works?

This thing really annoyed me, because airplanes for example are allways well spotted and the crew tell me about them, but it is not the case with ships.

Thanks everebody.

Note: My version is 1.2, and Mods are this:

Accurate German flags
Ambient underwater Sfx
Better torpedp Grap
Ferocius
Force camouflage
Germanu U boat Hydrophen
IRAI_0_0_10_bythedarkwraith
NewsUIs_TDC_6_8_0_bythedarkwraith
RAF bomber
TDW_Add_On_Mods
FX_update the dark..
Northatlatnticgreen 1.1
Equip_upgrades_Fix_AFFOE