Sonarman is generally correct.
1 BO: Goes without saying. No BO, no sub. The BO nuanse is that he, in addition to identifying the level of sub you move to, will provide SD (soft defense (important) in the lower level subs. I vet him. I begin to de-sailor him as I approach the 700- 900 SD range, to reduce sub loading. Other sailor (eng/rep/rest) functions become more practically important
1 Plansman: Absolute need. You can't submerge without this guy. Vet him to the max. Absofarkinlutely. Higher level, higher vets = quicker re-air time. Remember, if you want to start out with a full air tank at the break, you wil need the sailors on this guy to be full.
1 Sonarman: Absolute need. Vet him. As you reach the higher levels, (+100) you can de-sailor this guy to reduce ship loading. But remember, sub positioning is everything. As you de-sailor him, you will reduce his range. Reducing your sonar range, will open you to the risk of enemy submerged subs gaining position on you if you can't see them.
It's a pick your poison type thing.
2 Torpers: Max vet your main/front torper. This is the torper reload key. Vet up the second, rear torper, but depending on the line, the higher level subs may not have a rear torper. I max vet my rear torper, but de-sailor him to the extreme as he reaches a higher level. I prefer to fight with my front torps.
So far, I don't think any of the higher level sub guys, recognized sub threat operators, will argue with me. At least I don't think so. :) My following will probably bring some personal preference comment(s).
2-3 Engineers: This function gives you OH (over heat) time. The lower level subs have room for 2 engs. Max vet them. Absolutely. Remember, the higher level subs will have room for a 3rd eng., and if you want to be competitive, you will need that 3rd eng.
The following suggestions are just that. In the earlier sub grind, you may not have boat room, but be mindful that you WILL get better, and move into a more powerful sub at some time.
1 Restorer: Max vet him. Suggest this one as a support sailor, over and above the 3rd eng. This guy helps you withstand the HH salvos.
1 Repairer: Max vet him. Suggest this guy as the last one to develop, but he will give you an edge in the higher level subs. When the HH, or a direct hit by a BB, takes your blue arrow down to the "0" point, this guy is who mans the pumps and pulls you out of a certain sinking... if it's possible.
As a note. Both the Restorer, and the Repairer, will have Engineering atributes. These guys work best on the boat. They will perform on the "upper row" but when there, work primarily for their Eng. atributes. Both will contribute to your SD value.
Not sure if any of that helps. I'm just a nooby sub player. There are some really good sub players that may disagree with me. I'll subordinate my comments to theirs.
I'm not a good sub player, just somewhat dangerous.
