Strats for sinking ships with the deck gun?

[RadinBM]

I'm pretty new to the game and I just can't figure out how to effectively sink ships with the deck gun...
Here's some questions
-With round is better? I find both ammo types doing the exact same thing but AP seems to be more effective

-Does it matter where I target? (like aim for the hull with AP and the deck with HE?)

-Is there a difference between AA and HE ammo when targeted at ships?

-Most of my rounds seem to do nothing but after 6 or 7 hits, the health starts to decrease after almost each shot, is there an explanation for this?

-Does range/velocity of the bullet affect damage?

-Is there armor on ships (again if AP > HE)

-Is it better to try and start a fire on *BULK* carrying ships or just do hull damage?

-Is fire being started on chance or happens when targeted a specific part (or increase chance)?

-Whats the average minimum rounds required to sink a ship?

-Do different ships have different armor or HP?

-What happens if you kill some crew members? Does it affect the time it takes to put out fires?

-Is there a flooding system?

[Dewgle]

Ship HP

It looks like a health bar, the devs even put a little "HP" text next to it but it is not a health bar and does not behave like a health bar. It is in fact a buoyancy bar. As the ship fills up with water and loses buoyancy, the bar will empty.
https://steamcommunity.com/sharedfiles/filedetails/?id=2919736006

Flooding system

Yes, ships in Uboat have a flooding system just like your boat. In order for a ship to sink in this game, you need to make as many compartments fill up with water as possible. Shooting the same spot more than three or so times is useless. Spread the damage around to as many compartments as you can.

It matters where you target

Firing AP ammunition at the superstructure isn't going to sink the ship. Aim for the hull, as low as you possibly can to ensure water gets inside the ship as water will help it sink. Spread the shots around fore, middle and aft.

AP vs HE

If you hover your mouse over the ammunition it should have a description pop up at the bottom of your screen explaining that AP does more damage to hulls and HE can still damage hulls but does more damage to crew and has a chance to set fires.

So use AP against the hull and HE against the superstructure to kill crewman and set fires.

Killing crew and setting fires

Just like your boat, the enemy ships will attempt to plug leaks and stop flooding. The less crew there are? The less they can stop flooding and repair leaks. Enemy ships in Uboat cannot pump out water (yet?) but they can stop flooding.

Fires kill crew and generate leaks slowly over time. If you light a tanker on fire there's a chance the petrol will detonate causing massive damage and helping it to sink almost instantaneously.

Armor on ships

Yes, it is harder to generate leaks on warships than it is on merchant vessels. Plan accordingly.

Range vs damage

Range does not effect damage, only the arc of the projectile.

Average minimum to sink a ship

Based on the above information you would be correct in assuming that it takes a different amount of shells to sink different ships. Warships need more shells than merchants and some merchants need more shells to sink than others. My average for sinking an Empire class is about 15 or so AP shells. More for Liberties and C3s.

Don't forget about your AA gun

You can use the 3.7cm AA gun to sink ships as well if you run out of 8.8cm deck gun ammunition.

[Pablos16]

Shooting APs just below the waterline & spreading the shots along the hull is my go-to strat.

[Grumpy Old Dude]

Originally posted by Pablos16:

Shooting APs just below the waterline & spreading the shots along the hull is my go-to strat.

this...multiple holes, low on the ship, all flooding = sinking target

[Red_Seven_]

I've yet to see a difference between hitting the hull as low (or just close to the waterline) as possible and spreading hits everywhere even above the deck level.

The only outcome I can reliably reproduce is hitting the same spot three times to get the buoyancy reduced by a certain amount. This might be due to crew trying to repair a hole which makes them easy targets.

Also spamming HE into the bridge/superstructure of a tanker has devastating effects and leads to the crew abandoning the tanker already after just five or six hits (if it didn't blow up anyways). This seems to be caused by massive crew damage.

Also hitting a freighter directly from the stern side can cause a lot more damage as you're obviously damaging multiple compartments at once of it penetrates through the ship.

[RadinBM]

This has been really useful and I appreciate the help a lot!

I still have one question tho, why doesn't the buoyancy go down in the first couple of shots?
Does it have to do with crew patching up or is there a certain threshold of the amount of water that needs to get in before it goes down?

Here's what I have found so far:
-AA does the same thing as HE so ig its better to use AA instead of HE all the time.
-Flaks are a very good option to do HE damage if you run out of normal rounds.
-Always go for HE against tankers, one fire, and it's done.
-As mentioned earlier, you can do a lot of damage by shooting the stern of the ship.
-HE can do damage on the surfaces (like the deck) of the ship if you've got the shot.
-Shoot AP further from your previous shot it's not necessary to shoot completely somewhere else. (ig they get patched up pretty quickly)