sonar range goes in steps according to some of the posts.
Range 10.5 >620,000
Range 11.75 1,160,000
Range 13 2,130,000
Its known that the FF and DD can detect SS without a sonar man but I have not seen any data concerning range and if it might vary with Nation, Level of ship, or exp of crew.
Its also known that an FF or DD with a sonar man will have increased detection range.
So the question arises....what is the sonar mans range if his true experience is less then 620,000?
Logically, (and thats a weasel word in this game), one would think it would be less than 10.5 but greater than an FF or DD without a sonar man.
Finally, it would appear that once your sonar man has reached the final step, or range 13, it is a waste to continue to add experts and vets as range will not increase. The only reason to add these sailors would be to gain more repair/restore stats. However, adding vets and experts to repairmen or engineers would be a better investment.
Obviously a sonar man can be skeletonized on an SS as long as one keeps the True Experience equal to 2,130K or greater so range is kept at maximum.
There is little need to create a Chief Sonarman. Although the sonar ability continues to grow at a faster rate, the repair and restore ability are either decreased or set to zero or less. On any ship that is involved in sub warfare, be it SS, FF, DD, or CL, it is better to have a higher repair, restore stat. So it appears to be best to limit sonar man to 1st sonar and not promote to Chief.
Any other info about Sonar men would be appreciated.