Attacking a convoy in Sea State 0?

[MarkShot]

I noticed on glassy smooth sea that, the enemy AI seems to be able to spot you at 15km. This was tracking a lone merchant. I was quite impressed with it that it decided to lob very high trajectory shells at me without any chance of hitting me. It probably just wanted to send me a message.

However, it has dawned on me that trying to use the attack scope to approach and shoot a convoy under such conditions will probably be near impossible.

On the other hand, I know that it is possible to shoot on sonar bearings without ever showing the scope. So, is that how Sea State 0 attacks are made; on sound bearings only?

Anyone do that?

I am thinking to do that and use bore sited pre-programmed TDC patterns for the launching. Comments?

Thanks.