Completing the Perisher Camp

[E.F von Schlippenbach]

I wonder if someone could clear this up, in the second mission I get confirmation that I am in range to attack the Walrus, I flood the tube and open the bow doors to simulate an attack.

But nothing happens next thing I am counter detected the fact that I am within the 3 mile zone.

Am I missing something....Thanks

Sorted and now onto SBS recovery