Help with sonar - "no target selected"

[ET2(SS) Pallak]

Hello, this is my first post. Love SH4. I am running 1.5 with TMO 2.0, and I am trying to make the transition from auto targeting to manual TDC use.

The problem I am having is this:
I am currently trying to attack a lone merchant ship at night in stormy weather. The ship can only be seen using the scope at a range less than 300 yards (too close to fire upon) so I am attempting to find a firing solution using sonar only. My sonar operator has no problem following the target and continually gives me a bearing of the merchant ship. Whenever I try to use active sonar to find a range to the target, It tells me "No target selected." If I go to the sonar station and ping manually, it sends a outgoing ping, but nothing is returned. How do you select a target with no scope?
I have looked through multiple tutorials, including the werner sobe sonar only tutorial, and I cannot find what I am doing wrong. (Maybe Werner Sobe just has a much more competent sonar operator. lol)

Please, if you have any insight as to what I am doing wrong, let me know as this is driving me crazy; it is probably something simple that I'm going to kick myself for.

I apologize if this question has already been asked and answered; the search engine for the site leaves a little to be desired (But isn't that true for all search engines any more?).

[Armistead]

If you move the sonar arrow with your mouse cursor you should hear the ship and see the green light come on down that bearing, just focus in on that bearing to ping, wait for return and send to tdc....the rest are in the tutorials. Seems they was a good sonar only thread posted recently either here or in mods.

You can also use the deckgun basically the same way, just shoot the gun down the sonar bearing, when you score a few hits it will catch on fire and easy to see.