Convoy Disruptions proccedure with the ipcs control

[kublai khan]

Hello everybody
I have this question:
Germans turn, the put a sub on 109 SZ, throw the two dices, result a 2 and a 3….so, 5 IPCs lost to Uk
If I playing with the classic IPCs bills, the UK return 5 IPCs to the bank? Or just move his track 5 ipcs less in the chart?
The question is because if the UK don´t loose in fact the ipcs, and just loose 5 spaces in the track, and in his turn, sunk the sub, where is the sense for the disruption because in fact, the UK don´t loose anything, too much probably?
And,
If it´s true that the UK must loose the 5 IPCs in the same moment of the disruption for the sub on germans turn, why exist this lines in the 2nd edition rules:
“Once your income, bonus income, and losses from convoy disruptions have been determined, the number of IPCs that
your power will actually collect this turn is calculated by adding your income and bonus income, then subtracting any
convoy disruption losses from that total. Collect that number of IPCs from the bank by having the banker add it to the
total number of IPCs in your power’s treasury”
I´m some confused with this point….thanks

[ColonelCarter]

Convoy disruption happens at the end of the collecting powers’ turn, not when an enemy power moves ships in. So, in your example, Germany put a sub in SZ 109. That sub has to survive until the end of Britain’s turn to roll for IPC damage. So assuming Britain can’t/doesn’t destroy the sub, when Britain goes to collect income, you would roll your two dice, getting a 2 and a 3. Britain would then collect 5 fewer IPCs than the sum of their production value and National Objective value.

[kublai khan]

Ok, thanks Carter….anyway, the rules are not enough clear about this point IMO
And really not sense…because any submarine comandant are going to be “on station” over a convoy and only look them until UK turn?..hehe…sorry…not sense…the convoy disruption must to be on the agressors time. Well, if the rules are in this way, just follow them.
Thanks again