You are welcome, tirta.
Well, try to think about it: raising your esm antenna or your periscope out of the water surface what kind of consequences could have? The most obvious ones are that they could be detected by radar, for example.
Then, if you think more about it you could realize that in order to stick the antenna/radar/periscope out of the water you first need to take your sub very near the water surface... If the weather is good, in daylight hours, someone on an airplane/helo could see the sub silhouette... (I do not know if this is modeled in DW but I like to think in this way...
).
And that's more: coming to shallow waters could means that you are (for example) forced to come above the layer (if there is one) if you were running under it with all the consequences of the case.
Another consideration: in daylight hours periscope/esm could be detected visually, too.
So it is more risky to stick them out then during nighttime.
If they will be detected or not depends on many factors, like the weather(clear/rough sea), range to nearest enemy platform, how long you keep them out in plain view and so on...
As you understand, using them can get you an almost instant ID of a surface contact but it also brings home some risks. So, it is your job as a skipper to weight the risks/benefits aspects and factor them into your current tactical situation to come to a conclusion about what to do or don't do