[oscar19681]

I noticed this before. But i,m not sure if its unrealstic. i have my doubts since i never heard of a u-boat being detected on the surface. But on the other hand a destoyer doesnt have to be submerged to use the hydrophone. and maybe they can detect a u-boat or other vessel on the surface that is outside of the convoy. But inside the convoy i would think the diesel would blend in with the rest of the engine noise of the convoy