It all depends on what your goals are. If your goal is to survive, then yes, staying submerged all day will get the job done. It will also get you removed from command when you return to port.
You see, your job is not to survive. Your job is to sink the enemy. I believe it was Grider who made a deal with his crew on the transit from the Panama canal that he wouldn't initiate any attack where they had less than a 50% chance of survival. They felt much better. That means taking the necessary risks to have your boat in fighting condition and searching the maximum number of square miles of ocean each day to develop the most targets. You can't search squat at periscope depth and 2 knots. If you do luck out and find a target, your batteries are half flat and you'll die in the evasion process. If you survive, your lack of production will have you removed from command and you'll be pounding sand on a beach somewhere it's really dangerous and you're not in charge of the risks.
Fight your boat! That means keeping on the surface every second you can so your batteries are at 100%. It means that when you sight a plane you dive.
NEVER FIGHT A PLANE. What are you going to do? Use your expensive, hard to replace submarine and crew of 60 to kill a cheap, easily replaced plane with a crew of one? There's almost no gain there at all. Or, as is more likely, will your expensive, difficult to replace sub and crew be killed by that cheap, easily replaced airplane at huge advantage to the enemy? Heads they win, tails you lose. Bad bet. Get down quickly and don't be spotted or he'll call his cheap expendable friends by the dozen.
ONLY STAY SUBMERGED for the absolute minimum necessary amount of time. When you're forced down by a plane start your stopwatch as you pass periscope depth. Descend to 90 feet and wait for the five minute mark. Surface immediately, don't pause at periscope depth to sight see, just pop to the surface. In five minutes there is no way another plane could have gotten close enough to hurt you without you having time to submerge again. You can detect them much better on the surface than at periscope depth. We're maintaining battery charge levels here and maximizing range.
When you're evading, every second you need to the thinking, "Why can't I surface NOW to get away." Every second you're submerged is minutes of recharge time and excess fuel consumption. I don't mean surface beside a DD. I mean surface when you have them astern by 3000 yards and can run away on the surface.
A submarine is a surface torpedo boat that has the unique ability to submerge when absolutely necessary for short periods of time. Fought that way, the diesel-electric sub is a devastating weapon. Fought like an ostrich it is an expensive impediment to the war effort.
I guess that means I have no opinion.
