WEll i am not using often the hydrophone myself but several patrols ago i installed the first avaibable radar on my VIIB and this night my last patrol ( around 38 000 tons for a month long patrol in nord atlantik :)) got a radar contact from my radioman.It seems was far enough and a 2 merchant(large and small).
In the darknest of night i just over the horizon the watch spotted the ship.I went to the radar while aproaching the target to check out is it possible to use radar manually and yes it did.I never knew it was possible.And on the green line shows up a distorbtion (hell i cant write this right way),a small and and a big one.And just down left on the screem there are some numbers, i guess its the distance (i never used that old radar :D). In any case was interesting playing with that toy,later just bombed the radar distorbtions and the line was clear again :rotfl: