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HOI4 Dev Diary - Naval Terrain

Today we are going to talk about Naval Terrain and start talking about some of the core changes to the naval game.

We felt that we wanted to make where you fight more important, and where possible give advantages to people fighting in home waters. The sea in HOI4 has previously generally been either “ocean” or “ocean in range of enemy land based aircraft”, and otherwise mattered little. That’s about to change!

To do this we are introducing several terrain types for seas. These impact what ships work best there, how mines function as well as some other stuff. In total seas are divided into 4 types:
ocean.jpg

Regular Ocean has no special effects, so its similar to plains on land.

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Fjords & Archipelagos come with some hefty penalties to big ships, but make it easier to hide (all numbers still quite work in progress btw!)

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Deep Oceans on the other hand are not good for light ships. They are also not good place to mine due to their depth and vastness. Subs like this area (mid atlantic gap = bae) because it is also easier to hide here.

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Shallow seas are a bit harder to maneuver well in, and not a great place for submarines.

There is also some possible modifiers on them:

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Arctic Water is a general bad area to operate in, wearing your ships down and causing potential accidents. It also increases casualties if ships sink for any reason. This modifier works much like Extreme Cold on land so it depends on the time of year and temperature.

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Some places in the world have quite a lot of sharks and there are a lot of stories of heavy casualties after the sinking of ships due to sharks. The USS Indianapolis is a famous example where due to several reasons, sharks among those, something like 75% of the crew were lost. It is honestly mostly a cool flavor thing though we wanted to have in ;)

Your performance in these are also affected by Admiral Traits. As we have shown a bit before your Admirals can now gain traits for different terrain types.

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  • Cold Water Expert reduces the impact of arctic waters
  • Inshore Fighter gives combat bonuses and speed when operating in Fjords and Archipelagos
  • Blue Water Expert gives combat bonuses and speed when operating in deep oceans
  • Green Water Expert gives combat bonuses and speed when operating in shallow seas
You might have noticed some strange colors in the screenshots above. We are adding some more mapmodes, but it’s mostly all pink and full of coder art at the moment, so you are going to have to wait a bit more to see all those. I am pointing it out because I need to show the terrain mapmode a bit to more easily show off the naval terrain across the world
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Around the Dutch East Indies several of the terrain types are visible (the colors on land in this mapmode are still in need of some tweaking btw). The brightest there is archipelagos with the other shades of blue being shallow seas and regular ocean and the darker areas is deep oceans.

This is what the Atlantic and Europe looks like:
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Notice the deep ocean in the Atlantic and the fjords around scandinavia.


That’s it for this today, next week we are going to start going over some of the more core naval changes. Seeya then!

Rejected Titles:
  • Naval “terrain” is an oxymoron, like “Military Intelligence”
  • SHARKS
  • Fjords, or how to make Scandinavia relevant this DLC
  • Not from the creators of Sharknado, comes SharkBlizzard
  • Podcat read a book about how horrible it was being on a destroyer in the arctic
 
So this new update will fix the U.S.A just spamming aircraft carrier. I tend to say away form playing the U.S.A. I see your art team hard at work making nice models will we have greyhound apc and M10 tank and better models for the U.S army. Airborne and rangers will be a plus. How well dose the navel doctrine effect navy build.
 
No, sharks did not cause USS Indianapolis to have a lot of casualties.

There are 14 living survivors of the USS Indianapolis sinking; I have personally met four of them as well as a number of people involved with the survivors' organization. I can assure you, from their firsthand accounts, that sharks definitely caused casualties amongst the men who spent nearly five days in the water before being rescued.
 
Can't wait for the expansion, great ideas. I hope there are some tweaks to "naval aviation" units and equipment. Non carrier air units should have a longer ranges and perhaps other planes should get a naval attack mission as well.
 
It's obvious you've never been to sea then. Small boats don't do well in the rough seas that are common in deeper waters. In calm waters, sure no problem, but wait until that ship with a 2 foot freeboard gets into a sea state of 3. All hell would break loose. Just look at the USS Wasmuth (DD-338), A Clemson class DD that was sunk because a storm caused two depth charges to explode.

Even larger ships could have a hard time while in storms on the high seas. A good example would be the USS Pittsburgh (CA-72) in this video. I'll grant you 100 foot waves and 70 kts winds arn't common, but a smaller ship would have floundered and sunk like the Edmund Fitzgerald on lake Superior

The Sea State and ship seaworthiness system could be an interesting idea to introduce into the game.

For example, simplify the sea state level as 1-5, every sea region has a sea state value (change over seasons). 1 is calm, 5 is very high (typhoon season in West Pacific or Gulf of Mexico, and the roaring forties/furious fifties).

Then, each type of ship has a seaworthiness value, destroyer=1, light cruiser=2, heavy cruiser=3, battleship=4. If seaworthiness >= sea state, the ship fight at 100% efficiency, when seaworthiness < sea state, the combat efficiency would be debuffed, say (sea state-seaworthiness)*25% (destoyer in a sea state 3 region has only 50% combat efficiency).
 
Have to disagree with this. Battlecruiser distinctions seem a strange sticking point when the Ship Class system is already pretty abstract. The game already treats a Scharnhorst Class (9 11 Inch guns, 31000T) a Kongo Class (8 14 Inch guns, 26952T) and a KGV Class (10 14 Inch Guns 42245T) as the same thing 'Battleship 2' with identical stats. And given the ever changing classification of 'what is a battlecruiser?' the current system works fine.

That said, I'm hoping that the general naval overhaul and refit system will allow for a lot more flexibility and granularity rather than just a few more standardised ship types across all nations (although a bit more difference between nations ships would be nice, it isn't required and I can see the benefits of the current system from a gameplay perspective). I want to be able to refit the Gneisenau with the proposed 6 x 15 Inch main armament, convert a KGV to the rejected 9x 16 Inch main battery design, or cover PoW and Repulse with AA guns and see if they can avert their rl fate. Best case scenario, you can tweak and upgrade to the point where you've ended up with stuff like the pre-treaty proposed G3 (a 'battlecruiser' that was essentially an Iowa class battleship, but in the 1920s) and N3 (a battleship with comparable armament to the Yamato, if not the mass and armour) class ships.

Complete tangent, but I'm surprised the N3 isn't in the game already as the British SHBB1 (while it's not an exact fit, it's at least a close as a Scharnhorst and a KGV/North Carolina), as it was actually a proposed design. I've never even heard of the 'Centurion Class' that's in the game atm.

I'm not to add more ship types here, both pre-treaty battlecruisers and post-treaty "large cruisers" still have the "battlecruiser" archetype. However, the diffirence between them (your 'Battleship 2' ships) is so large that cannot be described using the upgrade points. The aim is to better modelling the the historical models and provide more diversed options. Yet I agree that a new ship design/refit system could be better off.

In the current game system, a ship is treated as a single "equipment". If you want to customize a ship such as changing main guns, you'll need a ship building interface similar to the division design system. A ship is no longer a equipment, but a "naval division" in which you can add and replace main/secondary guns AA/ASW weapons, or radar/sonar components as battlalions in land units. For example, when designing a battleship, you'll have "2x15inch"/"3x16inch"/... in "main gun" category, and can choose to activate 3 or 4 slots. The more turret you have, the more displacement and cost you'll get. Same for secondary guns and AA/ASW weapons.
 
There are 14 living survivors of the USS Indianapolis sinking; I have personally met four of them as well as a number of people involved with the survivors' organization. I can assure you, from their firsthand accounts, that sharks definitely caused casualties amongst the men who spent nearly five days in the water before being rescued.

NOTE TO PARADOX: These guys spent 5 DAYS in the water. In arctic conditions, you would be lucky to survive beyond 5 minutes. I therefore submit that there should be a temperature gradient on survivor rates on sinking:
Tropical waters: -20% casualty
Mediterranean: -
Cold (English Channel/North Atlantic) : +15% casualty
Very Cold/Bitter: (North Sea): +30% casualty
Icy: (Norwegian/Icelandic): + 40% casualty
Arctic: +60% casualty.

Shark infested waters: +40%, so Indi survivors get -20% for the warm seas, and +40% for sharks. Ok sharks are a LOT more scary but your chances of dying are actually higher in the North Sea or North Atlantic, let alone Icy waters, which kill in under 4 minutes.

The difference here is the amount of horror involved, which probably biases the actual numbers.

I mean which way woudl you rather die? Thermal exposure in 4 minutes, or being munched....
 
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I think the discussions about sharks and arctic waters and all might be overcomplicating the whole thing a bit. Sometimes a critical hit (think HMS Hood) will kill (almost) everybody, other times they will have plenty of time to go into the life boats (think a cruiser slowly sinking after being hit by a single torpedo from a submarine that subsequently was sunk by destroyers). In neither case would sharks be a factor, and possibly not arctic waters either, provided everyone got into the boats.

So, maybe just assign a random number of casualties from each sunk ship just to keep it simple?
 
I too think that survival rates are too high for lost ships.

Similar to Halvorni above I would be in favour of a base survival chance per sea zone with a random variable on top. In Hoods case, note that the actual survivors is not the actual number who escaped the ship herself (which was still a very small % of the crew).
 
I think a clear water modifier should be added in places like the Mediterranean and the Caribbean where you can see the subs in the water from the air (or sea if you are close enough) also the movement penalty for deep ocean should be taken of small ships and instead that should be a weather modifier (like mud).
 
Now it really makes sense to have different fleet compositions depending on the area of operations. And, as an extension of that, fleet hierarchies: Fleet -> Task Forces -> Squadrons
 
For those who seem to be disagreeing....

Blue Water Navy is capable of operating across all oceans and seas.
Green Water navy is capable of operating on a regional sea basis
Brown water navy being coastal and inland waters.

But with no clear borders between them.

According to Wiki - Brown water now means (for USN) inland with Green now including coastal waters.
True, but only fairly recently. I did some "research" about that topic in one of the last DD:
https://forum.paradoxplaza.com/foru...dding-and-traits.1117516/page-6#post-24628799

So imho it should've been called "Brown Water" here, too (and in Victoria II that didn't seem to be a problem)
upload_2018-10-12_10-55-47.png
 
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...[snip]...
I don't have a problem with the term being used, just repeating what earlier posters in the thread surmised :)

OT - I do hope Concert of Europe gets it's act together over the progress of non-civs and pop growth balance, so that I can dust off V2 again, superb game.