[Jimbuna]

What you experienced could be down to a number of factors...some of which you may have been able to determine if you hadn't increased your tc at a crucial/critical time.

When the enemy are in close proximity your better off keeping tc to normal time if possible to enable/help you witness any sudden changes in course or direction, the commencement of zig zagging or active pinging....all of which are a clear indication they are aware of your presence.

Try not to lie broadside on to your prey becuase your cross sectional profile is at its greatest and therefore easiest to detect. better to have your bow pointed towards them and your boat set at 'silent running'.

If I hazard a guess at your demise I'd say he picked you up on sonar and zig zagged towards you but your game was in accelerated mode and therefore you weren't able to notice the tell tale signs.