Los Angeles Class Nuclear Attack Submarines are a class of US nuclear-powered sub, first being built in 1972, and continued to be built until 1996. They succeeded the Sturgeon class subs and were later surpassed by the Seawolf class submarines. They are also referred to as the 688 class, named such after the number of the first ship in the series, the USS Los Angeles (SSN-688). Each is named after a US city, i.e. Los Angeles, New York, San Francisco, and Boston, with the only exception being the USS Hyman G. Rickover. These were also the first subs to break USN naming and use major cities instead of names of sea animals, such as the USS Nautilus. After 31 boats were built, an upgrade was added to all new ships which introduced a VLS system, known as the second "flight." The last major upgrade was the 688i improvement program, which made the ships quieter, gave them better sonars, electronics, and advanced noise reduction tech. With that short history lesson aside, let's dive in!

• Speed

While real Los Angeles class subs are reported of speeds over 25 knots by the DOD, the actual speed of these subs are classified information. In-game, the subs are shown to have a maximum speed of 33 knots. The only submarine that outruns you in Cold Waters is the Alfa class submarines, of which there are very few of during the '84 campaign. They will often appear closer to the Soviet shoreline, and do not often head out further. The Alfas also protect the Typhoon class ballistic missile submarine, found in the last mission. Most of the time, however, you should be cruising at a steady 5 or 10 knots to get the best sonar signatures and also to make yourself quieter. When firing, it is important to note that torpedoes launched at speeds over 15 knots can jam the tube, making them inoperable until you repair at Holy Loch, which takes 12 hours. Don't do it! (like how I just did 14 minutes ago) Also important to know is cavitation speeds, which is when the difference in water pressure causes the water on your propeller to boil, creating loud bubbles when they cavitate, or burst. Cavitation is one of the worst mistakes you can make while driving your sub, as it is incredibly loud and can help your enemies detect you easier. Here are the cavitation speeds at different depths.

• ~10kn @ above 100 ft
  
• ~15kn @ above 200 ft
  
• ~20kn @ above 300 ft
  
• ~33kn @ above 560 ft

• Armament

You have a small selection of weapons to choose from in the Los Angeles, which includes:

• The Mk. 48 Wire-Guided Torpedo
  
• The UGM-84 Harpoon Anti-Ship Cruise Missile
  
• The MOSS Active Decoy
  
• The TASM and its brother, the TLAM

Each of these will have an individual section on purpose and deployment.

• Sonar

The bread and butter of any submarine, sonar is a sensor which transmits and receives high-frequency pulses. There are two different types of sonar usage in Cold Waters, which will be discussed in their own topics. Passive sonar and active sonar have different uses and can mean the difference between eternal patrol and a successful kill.

• Other Sensors

The Los Angeles also has a multitude of other sensors, which shall be shown in a different topic.

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The Mark 48 wire-guided torpedo is your primary weapon of choice during the campaign. The version most likely in game is the MOD 4. It is a wire-guided (which means you can control where it goes) torpedo with its own ability to seek out targets as well. The Mk. 48 is forgiving to new players, as it is a very smart torpedo, automatically evading enemy countermeasures and plotting the best routes to target. HOWEVER: Once the wire breaks on a Mk. 48, it's a loose canon and will target any ship it sees, including yourself. Be smart about how you deploy them, and don't hit yourself in the bum, because you won't kill yourself. I will kill you when I find out that you wasted valuable weaponry on looking like a fool in front of those Ruskies. Just think that the Mark 48 is like that little chihuahua that humps everything, it'll go after dead ships, ships that are sinking, yourself, the lamp post, etc.

In order to fire a Mk. 48, you must have a target first. Yes, you could just fire a torpedo randomly, but if I catch you acting like some kind of hip-firing cowboy who shoots first and asks questions later, you will be quickly and forcefully relieved of your command. Once you have a target and have a high enough fire solution plotted, get ready to fire.

Before you fire, take a look at the bottom right diagram on your screen showing 4 torpedoes. The image informs you what type of weapon is loaded in the tube. If your tube has been jammed from damage or from attempting to fire from high speed, there will be no weapon icon and the tube itself will be colored red instead of gray.

You may also notice three buttons to the right of the weapon picture. The left button changes whether the torpedo uses active or passive homing. Active homing means the torpedo emits a sonar pulse, improving accuracy and increasing the chance for the torpedo to lock on to a target. However, this means that the torpedo will be very loud, which will alert enemy ships to the torpedo earlier than passive homing. It is best recommended to use active search against targets with a poor firing solution if you have to fire and then evade their attack. Passive search is the quieter approach, instead not emitting any sonar pings but quietly detecting sonar returns. These torpedoes are better for targets with a good firing solution and if you want to stay stealthy. For the majority of the time, you will probably want to stick with passive search. As the torpedo gets closer, any enemy ship with sonar will notice the sound of the torpedo's propeller as it moves through the water, so they will begin torpedo evasion maneuvers.

The middle button controls which direction it goes after launch. By default it is set to a snake search pattern, but can be changed to turn either right or left after activation by left clicking on the button. The snake search pattern makes the torpedo turn left and right along a straight course, automatically tracking any detected target. Left and right turn search modes make the torpedo swim in a circle once they activate, which can be useful in area denial tactics, as enemy ships will avoid the torpedoes.

The right button is the depth control, which controls whether your torpedo goes high or low after going active. Set this depending on the depth of the contact, for surface vessels you would use shallow running, and for submerged contacts below, use low search. The search cone for the Mark 48 is large enough to detect most targets above and below it, but it is unlikely a torpedo launched by you at 1000 ft will track a surface vessel.

To fire, press TAB to open the map. Left click on which tube you want to fire from. The Los Angeles has four tubes, two on the left and two on the right.

Press SPACE. This allows you to set a waypoint for your torpedo to track to before activating. You should see a box and a line coming from your ship, with range and heading labels showing how far and what direction the torpedo is going to go. Keep in mind that firing a torpedo from the opposite side of the submarine from your target increases the chance of a wire break. To decrease the chance of wire breaks, a common method is to fire the torpedo directly in front of you, and then change the course of the torpedo towards the target once it has cleared the submarine.

RIGHT CLICK to fire the torpedo. While it's running, let's talk about the waypoints. Torpedoes don't come out of the tube actively seeking targets. Instead, they travel to a pre-determined waypoint and activate once they reach the set location. You can change this at anytime by selecting the tube the torpedo was fired from, and then left clicking on the waypoint to set it to a different position. Right click to set the new waypoint location.

Once the torpedo has gone active and has acquired a target (which will be reported to you by your crew), you will notice the search cone turn red when the torpedo has acquired a target. By using the numpad keys 4, 5, 6, and 8 like arrow keys, you can move your torpedo around after it has been activated.

If all has gone well, then you should see something like this!

There's another guide that goes much more into depth on wire-guided torpedoes than I did, however, titled On Wire Guided Torpedoes .

The UGM-84 Harpoon is an anti-ship missile widely produced by the United States and is used by aircraft, ships, and submarines. The Harpoon in-game is tube-launched, meaning it has to be loaded in a torpedo tube. They cannot be launched under 200 ft, meaning you have to come close to the surface to fire, putting yourself in danger. They are also very loud, due to the rocket motor attached to them to propel themselves out of the water, and can be easily spotted due to the large smoke trail after launch. Be careful, because as soon as you fire, every red commie and their mother will come after you. It is highly recommended to only fire these off if you are not in immediate danger and fire them in salvos. They do have a chance of being shot down by enemy CIWS (close-in weapons system), so they cannot guarantee a kill every time one is fired at a ship. Firing these is the same as shooting a torpedo: Select the tube, press space, right click to set the activation waypoint and fire. These only have two modifiers: search area and attack approach. These must be set before launch, as after launch there is no control over the missile. Wide search is what it says- the missile searches a wide area for targets after activation. Narrow search is better for hitting single targets in a group. The most important setting is the attack type. Normally, Harpoons will attack at low altitude, parallel to the horizon. Using the top-down approach will make the missile arc up and climb before it turns back down and attacks the ship. Note that due to the Harpoon's small size, it is easier to avoid being hit by CIWS but has a smaller warhead and is slower than other ASMs (anti-ship missiles). An effective tactic against ships with sizeable CIWS defense is to fire more than one missile to overload the guns. Set one to surface skimming, and set the other missile to top-down attack. When both missiles reach their target, the guns must either choose to attack the missile at sea level or the missile coming down from above.

The MOSS is a strange device, mostly because its usage is not as a weapon, but instead as a decoy (but that doesn't mean you can't use it to ♥♥♥♥ up the enemy by drawing a torpedo towards themselves). Firing one of these can encourage the enemy to fire at the decoy, because it sounds like a Los Angeles. Once you've been fired upon with a torpedo, you can confuse a torpedo by firing a MOSS its way. You can try and confuse enemy sub hunters and draw them out at the start of a battle by firing a MOSS in a random direction, which can help you sink isolated merchants or capital ships, or just take them out one by one. It's not wire-guided, so when you fire it it just goes whatever direction you sent it until it runs out of fuel and self-destructs. I would recommend only bringing 2 on your submarine. These simulators also cannot change their depth, so it's best to fire one off to confuse passive search sonars above or below the thermal layer.
Addendum: Quote from a helpful commentor: "I'd like to note that the MOSS is beastly if used properly, that is: in tandem with decoys and knuckles.
As you well know, if a torpedo homes on a decoy it will break off pursuit of your sub in one direction. Firing a MOSS in that direction while steering in the other and going to Ahead Flank, then changing depth has a solid chance of making the torpedo chase the MOSS, overtake it, break off, chase after your decoy, circle around, chase the MOSS again and eventually just circle the MOSS until it runs out of juice and explodes. Even if that fails, chasing after a MOSS will cost a torpedo far, far more energy than going after a decoy.
Also, it's quite possible to trick enemy torpedoes that are far enough out into going after a MOSS fired at an enemy ship, and subsequently that ship itself. I've managed to sink a Delta-III in the final mission with a Soviet torpedo thanks to this mechanic."
Another satisfied customer.

The TASM and the TLAM are both the same missile body design-- the Tomahawk cruise missile. The TASM variant is an anti-ship version, with the same functions that the UGM-84 has. While it is bigger than the Harpoon, making it an easier target, it is also faster and has a larger warhead. The TASM has the same launch parameters as the Harpoon, which means using similar tactics will also be effective. The TLAM, the land attack version of the Tomahawk, is used during land strike missions. They have an incredible range of up to 2,000,000 yards, meaning you can fire them 100 miles from the target and still hit. In-game, they will automatically seek targets at ports to destroy. There are no launch parameters for you to set for the TLAM besides activation point. You must be above 80ft in depth to launch the weapon. When conducting a port strike, you can fire as soon as you first deploy in the zone, so take the initiative and do so immediately. Aim the missiles at the port icons on the map and they'll search for their own targets. Once the missiles are away, make sure to immediately load a MOSS or two and make a beeline for the disengagement area (the red border on the map). Every single enemy unit in the area will become alerted to your presence and they will be very, very pissed at you. So after you've kicked up the hornet's nest, make a run for it and you should end up alright.

Occasionally HQ will send you back to port to receive a team of special operations soldiers. Click on the "Load Special Forces" button in the armaments screen while in port to pick them up. Once you have equipped a team you will only have enough room to carry 4 weapons in the tubes, so choose wisely. When executing a spec ops strike, exercise extreme caution upon approach to the target area. You must avoid contact with enemy ships and disengage immediately if you enter combat with any vessels. If you choose to stay and engage enemy ships while you have spec ops on board, you will die. That is almost assured. Don't try it, but I know some of you will anyways just to flex your skills. On the campaign map head towards the target port and hold the right-click button to travel slower. If your target port is Murmansk, for example, move the submarine towards the map name until your XO automatically tells you that you have reached the target area.
You will be dropped into the in-game world to travel the final distance to the target. On the map will be a circle denoting where you must travel to. Move in as silently as possible to the deployment zone. When you reach any point within that circle, come to a stop and rise to at most 100 ft depth. Wait for a moment until you get the message that the spec ops team has departed, and then you may leave the area. As you are coming towards dry land, the sea floor will be very shallow and you will not have much room to move around or operate effectively. The best method is to travel far enough above the seabed not to worry about striking the bottom but also ensuring that you are deep enough to avoid surface patrols in the area, anything more than 150 feet is acceptable. When the water gets more shallow, you can drive the ship to follow the contour of the seafloor until you are within range. Make sure to avoid mines, as striking one can be enough to cripple or sink your ship, and all enemy vessels in the area will be alerted. While speed is vital to reduce the risk of having to engage enemy ships, you will spend most of the mission traveling at a speed of ~15 knots due to cavitation avoidance. I strongly advise that you do not fire any weapons while on approach, as numerous enemies will notice any weapons you fire. If you are being tracked by an aircraft or a ship, use a MOSS to draw them away from yourself. Traveling at slow speeds and hugging the seafloor also helps to hide yourself from the sonar of enemy ships. Once those spec ops are off the ship, your job is complete and your first priority is to immediately get the ♥♥♥♥ out of there as fast as you can because spending extended periods of time near enemy docks will result in you being found and destroyed.

In essence, working with spec ops boils down to these points:

• Do not engage enemy vessels.
  
• DO NOT ENGAGE ENEMY VESSELS.
  
• Travel at slower speeds to avoid detection during approach to the target
  
• Do not fire any kind of weapon, and actively avoid using the MOSS when able.
  
• Avoid minefields and stay low

When preparing to disembark spec ops:

• Ensure that you are above 100 feet
  
• Ensure that you are within the circle marked on the in-battle map
  
• Ensure that you are not moving (0 knots)
  
• Wait for a moment
  
• Leave when the message says the soldiers have departed

Sonar is one of the most complex tools you will use and is also the most important tool for the job. Sonar in-game is represented in the waterfall graph, showing a large "waterfall" of lines. These lines are constantly streamed from top-to-bottom, and sonar returns show up as bright lines that stick out. Note that the faster you go, the more interference fills your sonar, which makes it practically useless above 15 knots. To keep things simple and not have to make this sound like a boring physics lesson, I'll explain it shortly.

---------------------------------------------------------\ENEMY SHIP/-------------------


|(YOUR SUB)

- - - - - - - - - - - - - - - - - - - -THERMAL LAYER- - - - - - - - - - - - - - - - - - -




_______________________OCEAN FLOOR_____________________

As shown in the badly-done graph above, you will notice the Sub is above the thermal layer, scanning at an enemy ship. When popping above the thermal layer, finding enemy ships is much easier, but it also makes it easier for them to track you as well. You can use this to your advantage, and pop above and below a strong thermal layer, hiding below it and popping above to scan and attack targets.

----------------------------------------------------------------\ENEMY SHIP/------------


- - - - - - - - - - - - - - THERMAL LAYER - - - - - - - - - - - - - - - - - -


|(YOUR SUB)

______________________OCEAN FLOOR______________________

As you can see here, the submarine is hiding below the thermal layer, which makes it harder to detect. However, this also means that the submarine may have difficulties trying to scan for ships on the surface. What tends to happen is sonar will kind of bounce off of the thermal layer, or go through it and begin to distort.
This picture from the in-game guide does a much better job of explaining it more in-depth.

While highly advised against and extremely unfavorable, if, for some god-forsaken reason, you absolutely have to know the position of an enemy vessel, then you may use Active Sonar. I shudder at the thought of it. Turning it on is basically suicide, as you what you do is turn on a flashlight in a dark room and shout, "IS ANYBODY IN HERE?" Meanwhile, everyone in the room who didn't turn their flashlights on before because they aren't stupid immediately turned around, pointed their flashlights at you, and stabbed you to death with 50 million air-launched torpedoes from those ♥♥♥♥♥♥♥ KA-27s ♥♥♥♥♥♥♥♥♥ WHY DO THEY HAVE SO MANY ♥♥♥♥♥♥♥ TORPED-------
Pardon me, I must've gotten carried away there. The only acceptable usage of active sonar is for "One ping only, Vasily." One ping, and listen to what comes back.
Jokes aside, do not use active sonar while scanning for surface targets. Their ASW systems are advanced and they will determine your location faster than you can say "Was that a KA-27 I just heard?" If you are attacking enemy submarines who have already fired a torpedo at you, then active sonar is permissible. Your sonar systems are light years ahead of most, if not all Soviet submarines you fight against. Also note that the Los Angeles is a hell of a lot quieter than any submarine you will run into, giving you a massive advantage in stealth during first contact. The Flight III or 688i mod adds acoustic tiles to the skin of the submarine, making it even quieter still.

This guide was created to present you with the basic concepts and usage of this submarine. While this may be a basic set of rules, do not be afraid to change up the playbook and work around whatever you run into. With all of that being said, I say "Happy hunting, skippers. May fair seas and following winds find you. And ♥♥♥♥ dem commie bastards. God bless the USA."