Advice: like someone mentioned earlier, surface some where safe to recharge and stuff. Once that's done, go out further into the ocean to test how far and how long you can stay submerged. It's a good idea to know the limits of your boat before attempting something as daring as this. Once you know these two factors then you are ready to go. Use your new data to measure the farthest point to submerge and farthest point to surface. Staying submerged is your safest bet. You can use you sonar to track any income patrols and know where to turn or when to stop or when you think it's safe to go at a higher speed under water. I recommend that you stay on silent run for the duration you are underwater. I did this once, but that was up at Dover Strait earlier in the war. Gibgraltar is very different but the same tactics should work, with some luck of course.
So I say all the best to you Kaleun
