[TorpX]

I guess TMO is a lot different here. I opened up a couple TMO files:

Deck Watch .........................crew exposure 0.3
most hull compartments..............................0.1
most guns.............................................. ....9.0

So, you're more or less right; watch crew is fairly safe. At least they are much safer than if they were left at their guns.

In RFB deck watch and guns are both vulnerable.

And straight from the TMO manual (written by ducimes):
7. Deck and AA gun crewman being killed while submerged. This is due to a design flaw of the game. Place your crewman in “hogan's alley” (after battery crew berthing) when not in use.

The design flaw really applies to all compartments equally. They can all be changed/modded to be as safe, or as vulnerable as we wish. It is just that their status does not change when we submerge or surface. So, we can either make the deck watch vulnerable (which makes sense when we are on the surface - not so much when we are under it), or we can make them protected (which only makes sense when we are submerged).

I guess Ducimus thought convenience should take precedence here.

In RFB, I recommend players send their deck watch below when diving. Hogan's Alley has empty slots, as does some other sections. The guns are only manned for very short periods, and those by torpedo room crews. It seems odd to me to have extra crew just for those.