While calorie counts vary with pizza toppings and recipes, a slice of cheese pizza (weighing about 103 grams) is around 272 calories, according to LiveStrong.com. A calorie counting website averaged a slice of cheese pizza at nearly 250 calories. Indulge wisely and check out these eight pizza deals for Pi Day. Read: The Best Pi Day Jokes. Villa Italian Kitchen: Customers can get a Neapolitan cheese pizza for $3.14 with a coupon.
The Navy's nuclear-powered submarines can stay submerged for long periods of time. Air is isn't a problem as their make their own oxygen and keep the air clean. The limits on how long they can stay underwater are food and supplies. Submarines generally stock a 90-day supply of food, so they can spend three months underwater. The diesel-powered submarines (not now used by the Navy) had a limit of several days submerged.
The depth a sub can go is classified but it seems to be greater than 2,000 feet. All US subs are nuclear powered. This type of propulsion doesn't require air. Electrolysis creates air from sea water. The limiting factor for how long a sub can stay under water and away from port is the amount of food they can carry.