SW England to Gibraltar route efficiency 5%, why ?

[DPP]

Then also SW England to Alexandria 5%.

I don't quite understand, I have ships on patrol and all the sea areas are green on the routes.

Any clues ?

 

[desphorin]

Being convoy raided? 5% is the minimum convoy efficiency after the route is being attacked several times. It will only recover after 7 days of not being raided.

You can get raided even if you have 100% escort efficiency. You need to ensure the convoy escorts have enough screening efficiency as well.

 

[Iskulya]

I've been noticing a bug lately where convoy efficiency remains at 5% for extended periods despite no convoy losses.

I experienced this in a game just today as the Soviet Union in invading Romania. The level 8 naval base in southern romania was giving me an efficiency of 5% despite never having lost any convoys. It actually remained this way for over a half a year ingame before it spontaneously reset. Never seen anything like it in 2k+ hours of playing, makes me wonder if this is a newer bug now that I see someone else mention it.