Mysterious damage?

[i_b_spectre]

I was leaving Lorient on my 18th GWX 2.0 combat patrol, had turned west between the mainland and the island at the mouth of the tributary, when suddenly I'm taking damage. I was on the surface running no more than 64x TC at 1/3 ahead, have not enabled Sabotage and Malfunctions in SH3 Commander, and got no word from the crew as to the cause of the damage.

The first time it happened, I exited the game and restarted the mission, but it happened again at the same locale. Both times I had damage in the forward crew compartment and in the electric motor room. The damage was minor, no flooding, and it didn't take long for a damage control party to get everything sorted out and I continued on my patrol. I'm always careful to navigate the middle of channels to avoid shoals, plus, the depth under keel was 11 meters. I'm relieved the incident was fairly inconsequential, but still, the source of the damage is a mystery. I've been in and out of Lorient many times without incident, but the GWX manual does show an anti-sub net extending southward from the mainland. Could that be the cause of the damage?