Me thinks that sea critter is overmodelled. Seriously, if you're interested in undersea warfare in WWII, you should read both "Run Silent, Run Deep" to get the American POV, then read "Das Boot" to see the other side of the coin. It's interesting to note how the success curves for the US Navy subs in the Pacific was the inverse of the German Navy's experience in the Atlantic.
In any event, those two titles contain a wealth of info on how subs operated in WWII. Generally speaking, subs only operated on the surface during the day when they were outside enemy aircover. With an air threat, they ran submerged from sun up to sun down (unless there was foul weather; then they took advantage of its cover), then ran on the surface during the night to recharge air/batteries. Normal submerged cruising speed was on the order of 4 knots, surfaced it was 12 to 16 (though 16 knots used an alarming amount of fuel).
Eventually, even the night gave the German U-boats no security to run on the surface. The British development of aircraft borne milimeter-band surface search radar forced the development of the schnorkel, but even that ingenious device was soon negated by continued improvements in radar technologies. Eventually, the Germans developed radar absorming material (RAM), but even this proved inadequate in the end.
The point of the interview article you should most appreciate is the part about how HTC looks to you, the player community to figure out what works and what doesn't. When subs at last join the AH stable of vehicles, it will be a fairly rudimentary implementation at first. It is the line drawing, to which we (the player community) will than add color, hue, and texture too. So keep those ideas coming, and don't get discouraged if the first release doesn't have all the bells and whistles you'd like. Just as ground vehicles were more eye-candy than true simulation when first released, so too will subs and ground troops start out pretty simply, to be fleshed out and improved as time and input allows.
