Yes, there were several. They were more prominent in the Pacific Theatre of the war than the European Theatre, however.

Ans 2 - There were 288 US Navy submarines in WW2.

The German U-boat S-20, under the command of Kapitänleutnant Walther Schwieger, sank the Royal Mail Steamship (RMS) Lusitania on May 17, 1915. The sinking was off the southern coast of Ireland, killing 1,198 of the 1,959 people aboard. She sank in 18 minutes.

The S-20 was patrolling the shores of the United Kingdom, under orders to attack any vessel (known as Unrestricted Submarine Warfare) as the Germans had considered the UK under a naval blockade for several weeks.

Schweiger noted that he only fired one torpedo, and that a secondary explosion was so large it caused enough damage that he didn't feel the need for a second. The cause of the secondary explosion remains a controversy to this day.

The resulting public condemnation of Germany was so great that Kaiser Wilhelm II ordered the German Navy to return to a policy of Restricted Submarine Warfare. This continued until 1917, when Germany again resumed its policy of Unrestricted Submarine Warfare in response to a British Naval Blockade.

It depends on the boat type (SSBN, SSGN, or SSN) as far as the rank of the Commanding Officer, but the CoC is essentially the same. It's not much different than other afloat commands in the Navy, though as with all nuclear-powered vessels, the Commanding Officer and Executive Officer must both have previously been qualified and successfully served aboard another vessel as an Engineer Officer.

Note:

The Ship's Corpsman (Doc) reports directly to the CO/XO.

The Chief of the Boat reports directly to the CO/XO. Though

the COB's rank is typically a Master Chief (E-9), it can be a

lower rank, such as a Senior Chief (E-8). Regardless of rank,

the COB is by virtue of position as COB the most senior ranked

enlisted member aboard ship.

Commanding Officer

(Captain or Commander, depending on boat type)

|

Executive Officer

(Commander or Lt. Commander)

|

Engineer Officer

(Lt. Commander)

|

Weapons Officer - Navigator - Supply Officer

(Lt. or Lt. Commander)

|

Division Assistants

(Junior Officers, in charge of individual Divisions)

(Lt., Lt.(j.g.), Ensign)

|

Chief of the Boat

(Senior Enlisted Aboard Ship)

|

Division Leading Petty Officers (LPO's)

(Chiefs or Senior Petty Officers)

|

Rated Sailors Qualified in Submarines

|

FLOB's / NUG's

(Free-Loading Oxygen Breathers / New Useless Guys

who aren't yet Submarine Qualified)

For the most number of enemy ships sunk, USS Tautog (SS-199), under 3 separate Captains, sank a total number of 26 ships, including warships and merchants.

For most ships sunk in a single war patrol, it was the USS Tang (SS-306), under legendary Captain and Medal of Honor recipient Dick O' Kane.

Early submarines had no effect on society whatsoever, as the first ones were built several hundred years ago. Even then, they weren't considered an honorable form of naval warfare, and the first submarine used in combat (Turtle, Revolutionary War) never amounted to much.

It wasn't until the Civil War and the sinking of the USS Housatonic in Charleston Harbor by the submarine H.L. Hunley that navies finally took notice. By the end of the century, the U.S. Navy had received its first modern submarine from pioneer John Phillip Holland, of Electric Boat fame. His designs were improved upon, but others followed in his footsteps with submarine technology. During WWI, the Germans proved to the world that the submarine was a viable military threat that had to be dealt with.

Arguably the biggest impact of the submarine on society outside the Housatonic was the sinking of the British passenger liner RMS Lusitania, which carried both British and American passengers. Many of the dead were children and luminaries of the day; the Lusitania's sinking is what brought submarine warfare to the forefront of society.

Here's the short answer: to preserve the night-vision of the submarine's crew, while retaining adequate color and depth-perception abilities.

The long answer? Well, to understand that, let me take you back, just before World War I, when early submarines were starting to come into their own.

Back then, all military vessels--surface and submerged--relied on red-colored lighting for night operations. The theory, at the time, was that red-hued light only saturated the red photo-receptors of a person's eyes, thus leaving the green and blue receptors unaffected. Hence, all-important "night-vision" could be preserved better by stimulating only *one* of the three photo-receptors (humans can see red, green, and blue, and have receptors for each of these three "primary" colors). In addition, red had the advantage of a high-frequency wavelength (about 560-570 nm). When coupled with a low-powered intensity of illumination (through lower wattage, typically 4-6 W; what your standard incandescent "night-light" puts out), the light effectively "died-out"; it was hard to detect from long distances. Perfect for surface-going ships.

But, how did this make its way to the world of the submarine?

Remember, early submarines were really not much more than surface-going small frigates (some would say, using the British term, more like "corvettes") that *could* submerge under water. Back then, submarines did the majority of their fighting "above-the-beam"; from a surfaced position. That's why all those old WWI-WWII era subs have huge deck guns--you're not going to fire that thing from underwater!

Instead, the purpose of a submarine was to stealthily sneak up on an enemy contact, quickly surface, fire off it's deck guns, and submerge before it could be fired upon. (Although torpedoes could be used, they were--for the time--fraught with unreliability, were expensive, and required the boat to remain on-station until impact--due to their cable-operated guidance--thus rendering a submarine highly vulnerable to counter-attack.) Thus, the deck gun was the most favored means of primary attack.

Most submarine surface attacks were carried out at night (I don't care what's depicted in U-571, that was a completely different, highly-desperate situation). Thus, transitioning from the enclosed, controlled conditions inside the boat to the exposed, uncontrolled conditions *outside* the boat had to be done as quickly as possible. As the ship came to Battle Stations, and subsequently surfaced, the Chief of the Boat would "rig for red," dimming (or extinguishing) all work lights, and lighting the red lights, so as to prepare the men for going topside, into the night. Remember what I said, a few paragraphs ago? By saturating the men's eyes with red-colored light, their blue and green "night-vision" perception was thus unaffected, making "recovery time" once topside much quicker!

In fact, this tradition is still used by submariners, to this day. When a sub surfaces, the lights are switched to red (as accurately portrayed aboard the USS Dallas in The Hunt for Red October). As Cpt. Mancuso and his XO go up to the weather bridge, the lights switch to red--the holdover from the old submariner days!

So, what's with the funky bluish-green lights, you ask? It has to do with two developments, namely: better understanding of how the human eye works, and advancements in computer-display technologies.

First-off, the human eye. By the mid-60's, scientists had discovered that red-light saturation actually *decreased* night-vision, to some extent. It wasn't necessarily the hue of the light that affects night-vision (though that fact is still debated), but rather the intensity of illumination. See, red-hued light requires almost *twice* as much illumination to provide the same candle-power as lower-frequency (420-460 nm) blue-hued light. Thus, red-light is prone to induce more glare, and will negatively affect the cones (photo-receptors) of the eye. Blue-green light at a *lower* illumination is actually better, providing more color "information" per degree of illumination.

Which leads to the second development...

Red light kills depth and color perception. Sonar operators--who relied not only on their well-trained ears, but also their well-trained *eyes* to interpret the sonar plot)--were reporting trouble reading their spectral plots in the intense red light (coincidentally, most sonar plots are now green-and-blue, and sonar shacks are *always* rigged in blue lighting). The Navy conducted many studies and tests, and found out--sure enough--that blue light would actually be better for *modern* submariners. Since they hardly go topside, now, to fire their armaments, the whole "preserving night-vision" mechanism is unnecessary. Instead, accurate color and depth-perception, especially when translating instrument output, is paramount. Again, using The Hunt for Red October, as the Dallas goes to Battle Stations, the blue lamps are switched on!

WW2

83,115 troops british and commonwealth troops and 73,000 American troops.

the German numbers aren't known accurately as they were depleted at the time but they did have 59 divisions in France, Belgium and the Netherlands not at full strength.

The number of Allied combat casualties on D-Day is approximated at

10,000, of whom 2,500 died.

Here is the breakdown of the casualties:

British - 2700

Canadians - 946

Americans - 6603

15,000-20,000 French civilians died with an unknown number of casualties.

Britain: 2,700 killed

United States: 1,465 killed

Canada: 500 killed

Germany: 4,000 killed

Axis Casualties:

9,000

Allied Casualties:

Estimated at 10,000; exact figures not available