The US subs were comparable in size to the Type IX, and as such, took longer to dive than the VIIs did. "Typically" they say (in wikipedia, such an "authoritative" source
) a Gato could dive in about a minute. The other boats from the Porpoise Class on up, were very similar in design and performance in that regard. With a LOT of practice, and some later modifications, a good crew could get a Gato to PD within about 35 seconds by mid-43 (again, using Wikipedia as the "source"
). I have read similar elsewhere, but do not recall that source... In RSRDC, expect longer times than that, due to the settings for "more difficulty" that the mod combination provides. You should have SD radar from the start on most of the boats, but I do not recall which ones do not in RSRDC. I am like 90% certain that an S-Boat will not have radar. You will get improved, and other model radars in somewhat "historically" appropriate times in RSRDC, but if you are in Fremantle, you must remember that you are at the end of the supply line... As Niume mentions, there were standing orders for the boats to be submerged by day, and only surface at night (basically) whenever they were within 500nm of a known enemy airbase. Of course, when the boats came back in from patrol, the first thing mentioned to them was the fact that they had taken so long to get to their patrol zones... spent too much time submerged...
