I got IJN sonar and planesman with stats 13 pot/11 rep/11 rest. I class them to suport sailors and lvling them.
I class them at lvl 95 to 2nd sonar and 2nd planesman, other class is bad, because you loose rep and restore abilities.
I got 200 vets on both sailors and its wonderfull, repairing and restoring is very good, 900 SD i got and they primary function on sonar and air is on cap now.

sonar and planesman lvl asap if u plan to play the ss1 2 and 3

wy sonar to see better becos u will fight ss vs ss battle alot and the better sonar gives u a ege
wy planesman simple the airrefill

if not u can leve them as suport sailor and then class them at ss4 lvl or even whait loger to around
lvl 100 and then class they will hit the cap then

some screen of me crew :)
http://i54.tinypic.com/20fuic9.jpg
http://i53.tinypic.com/20k7j21.jpg

The time to level crewmen depends on which type of sailor you will have them be at the end of their carreeers. For instance a gunner will always be a gunner, but a support sailor can and will do a bit of everything. If you sit both the sonar and planesmen on your support dock without classing them up to sonar/planesmen then they gain benefits in all areas where as if you class them up to sonar and planesmen their "Net Gain" is far below their "Net Loss" on all skill categories. The goal of a support sailor is provide maximum sonar, air, engines, repair and soft defense. It can be difficult to not pull the trigger and class up the sailors when 1st offered, and its not a bad idea either however if you reach the highest lvl's in the game your sailors will reach a speed cap, sonar cap, air cap, soft defense cap, ect...

So why would you want to class up a sonarman and planesmen when your SS1 is worthless and you will be miserable in it? The answer is none. Do not class up either until your ready to put them to use in SS2 or SS3.

PS... It also matters what the base stats of the other categories are, not much benefit if the base repair is +5 with +15 potential.

A sub without a sonarman can only see about two sub lengths in any direction.

So wait, if you class a planesman at level 30 he won't refill air faster than a planesman classed at 90?

I figured the sooner you class them, the better they are at what they do. A support classed at 90 to planesman should be much worse at refilling air than one classed at 30, no? That's 60 extra levels of planesman to refill air faster but at the expense of rep and rest.

My planesman is 30, and now I don't know if I want to class him.

The testing regarding how much a sonar man's true ability (and possibly his class) affects sub detection range has never been complete, and much doubt is cast on the discussions and limited testing you can find on google because of continuing tweaks to game mechanics. Some of the detection range testing I have read about saw bizarre results that were blamed on unreliable glitches.

There is a chance that now or in the future, not classing your sonar man when you "should" will result in poorer detection abilities.

However:
- The affects of sonar man on submerged vision distance (vs. surface ships/planes/etc) are well-documented and easier to test. These are the "steps" you have probably read about, and the lesson is that zero true ability is just as good as (edited) 500k... the first step is somewhere around 600k or 800k (I'm not exactly sure where).
- The popular opinion, which has already been stated here, is that the difference between a bad sonar man and a good sonar man is small enough to justify the gains you'll see in repairs and restoration.

Just remember that a sub with no sonar man cannot see submerged enemy subs at all. Only FFs and DDs get "free" sonar.

Should one convert the Planesman to Chief Planesman? You loose the support aspects if you do.