Retention: Good Boat Vs. Bad Boat

It looks like JO retention numbers have been pretty good lately for the Submarine Force, as evidenced by this announcement that PERS42 is going to a "Two Look" Department Head screening system. Excerpt:
The primary driver for changing the Department Head screening process is strong retention trends among our junior officers for the past two years. This strong retention has the potential to significantly impact Department Head tour lengths, which are already at the minimum required to provide adequate operational and leadership experience, and has the potential to reduce Executive Officer screening opportunity. As a result, we are shifting to a two-look Department Head screening process and will not return to a one-look screening process.
The screening board will look at each year group (YG) twice, in May of the fifth and sixth year of commissioned service. Since YG05 has already passed its first look date under the new process, YG05’s first look will occur in November 2010, followed by a second look in May 2011. YG06 will have its first look in May 2011 and its second look in May 2012.
The Submarine Force will always provide high quality officers an opportunity to serve as Department Head. Officers who have performed well during their Division Officer tours should not be concerned about Department Head screening. We anticipate that few officers will be placed "not cleared" on their final look. However, the Submarine Force must maintain control on the upper limit of the number of Department Heads in order to ensure each officer who does serve gains the experience necessary to develop professionally and be fully prepared for follow-on assignments.
This announcement, plus getting the retirement announcement for one of my fellow JOs on USS Topeka (SSN 754) back in the '90-'93 time frame, got me thinking about my JO experience and how the boat "command climate" impacts retention. Topeka during this time was almost legendary for having an "unpleasant" CO -- "He Who Must Not Be Named". The thing was, we ended up having good enlisted retention, and JO retention seemed to be above average. Of the cohort of 10 JOs who did all or most of the boat's '92-'93 WestPac/Arabian Gulf run, we ended up with three who got out of the Navy before their DH tour (one of whom was transferred off the boat early when he made a 1MC announcement to the effect of "I'm LTJG XXXX, and I'm drunk off my ass" when he was brought back to the boat off liberty when they were pulled into Bangor for voyage repairs), and two did lateral transfers to other communities before their DH tours (Medical and JAG Corps). That left 5 of 10 who went on to serve as Submarine Department Heads, and three of those went on to command. My theory is that the above average retention was due to a couple of factors: 1) We all developed a very strong sense of "Team", in that we were united against the common enemy (the CO), and 2) We knew -- as an absolute fact -- that we would never have it worse in the Navy in any future assignment. It would all be downhill from there.

What do you think? Does the command climate of a submarine influence the boat's retention rate? Or is it mostly the ship's operational schedule that's the driver? Or a combination of factors?