Cargo Ships added to an existing game
https://prnt.sc/kaQ1rjbiArrL
explore the unknown map
https://prnt.sc/sROb0ln26GRy
no offshore oil found or im blind ;-)
default settings

--EDIT
found a single one ;-)
https://prnt.sc/mjjTHfktSusP

--EDIT
create a new game, default resource settings
https://prnt.sc/4whmnVYNKI10
where is the offshore oil?

You have lots of other ores spawning in water… maybe some conflict with whatever is doing that?

i just have more water, and the ore doesn't care, it would be in the same place if there was land. but since i have more water, there should be more offshore oil as crude oil.

Look in the log for messages about creating offshore oil deposits. With standard oil frequency, there just is not very much on the map to begin with, so it takes quite a coincidence for it to be in water.

The caveat is that by default, the oil just gets deleted from shallow water. If most of your map is shallow then that might explain it. The log will show if that happens.

but I don't have shallow water.

but I don't have shallow water.

Shallow in this case means "not 'deepwater'". Normal 'water' is avoided if the "no oil in shallow water" setting is enabled. Your map there has a lot of 'water' because of all the coastlines.

But like I said, look in the log file as you explore the map. Every time a chunk is generated, it checks for oil in water and does something with it, and logs it. You can see if it's finding any at all, or if it's deleting everything for some reason.

You can also try disabling offshore oil altogether since you already get ores generated in water. Then see how much crude shows up with your seed.

search for "oil_placement.lua"
Zeile 951: 9042.801 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 4 of 9 crude-oil in LAND chunk [43, -39]
Zeile 952: 9053.468 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 4 of 6 crude-oil in LAND chunk [43, -40]
Zeile 953: 9055.601 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 1 of 1 crude-oil in LAND chunk [44, -40]
Zeile 954: 9057.402 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 4 of 4 crude-oil in LAND chunk [44, -39]
Zeile 955: 9104.669 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 1 of 1 crude-oil in LAND chunk [49, -1]
Zeile 1004: 11608.069 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 3 of 3 crude-oil in LAND chunk [-30, 45]
Zeile 1009: 11638.535 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 4 of 7 crude-oil in LAND chunk [-31, 45]
Zeile 1012: 11785.336 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 1 of 1 crude-oil in LAND chunk [-14, 54]
Zeile 1013: 11785.402 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 1 of 1 crude-oil in LAND chunk [-13, 54]
Zeile 1014: 11785.734 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 2 of 3 crude-oil in LAND chunk [-14, 55]
Zeile 1079: 14197.135 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 1 of 4 crude-oil in LAND chunk [-20, -58]
Zeile 1080: 14214.201 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 0 of 1 crude-oil in LAND chunk [-20, -59]
Zeile 1083: 14312.437 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 0 of 1 crude-oil in LAND chunk [4, -58]
Zeile 1084: 14312.972 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 0 of 4 crude-oil in LAND chunk [5, -57]
Zeile 1122: 16160.802 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 3 of 3 crude-oil in LAND chunk [59, 28]
Zeile 1123: 16161.902 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 2 of 8 crude-oil in LAND chunk [60, 28]
Zeile 1124: 16161.903 Script @cargo-ships/logic/oil_placement.lua:55: nauvis: Deleted 0 of 1 crude-oil in LAND chunk [60, 29]
no other entries found

Did you check the "no oil on land" option? This is showing that some oil did in fact generate on land and was deleted If you want only offshore oil, you have to turn the frequency way up.

No, I just wanted to test the rig; so I looked for offshore oil, but didn't find any.

I always find it to be rare unless I turn the size of the oceans way up. In vanilla there's not that much oil to begin with.

I have plenty of oil onshore and if the mod offers to provide offshore oil as well then that should work, if not I have to ask why it doesn't work.

It doesn't "provide" offshore oil specifically. It lets the oil generator ignore land vs water, and if it is in water, with enough empty water around, then it's made into offshore oil. It doesn't put offshore oil near the coastline so that building waterways is easier.

That way it is repeatable based on the seed, versus the legacy method of adding it randomly based on the order chunks were explored. I haven't wanted to spend time changing the system again. But that means it's sometimes rare on maps with a lot of land. If you want offshore oil, you need to make a map with actual oceans instead of lakes.

the logic is clear and ok, the problem is i have a lot of water. coverage is 400% , but scaling ist 25%
what ist the definition of "with enough empty water around," may be this is the problem.
In the log i dont see any deleted oil on water, this is strange, because there should be 400% more. not logged?

There has to be an entire 16x16 chunk with no land to allow offshore oil. You will have to turn water scaling up (like 200%) to get larger individual lakes

OK, that could explain why there is no offshore oil, there are max 4 chunks of water between coasts and not 16.
but it is not logged that oil in water is deleted. but since I do not find one. it can only have been deleted
if this is true, i need to disable the offshore oil option, otherwise i will have less oil on the map than provided by the map generator.
will deleted oil fields on water be replaced with oil fields on land if no offshore oil field is placed?

The log you pasted says e.g. "Deleted 4 of 7 crude oil in LAND chunk". That means the deposit was on the coastline and the ones in water were deleted. They are not replaced.

If you don't plan to play with large bodies of water, then yes you should disable offshore oil.

I'm open to pull requests with improvements to the algorithm, but it works fine for most people. If you plan to play with lots of tiny lakes, what will you use ships for? You might not need this mod at all.

I have no small lakes, but a maze of land and water. with 400% water. I can build tracks on land and use bridges (if i kill all biters which destroys the rails), but I wanted some variety, so I use content mods ;-)
I don't have resources to hack yet another mod, but if I did, I would change the logic to replace all the related oil fields in the water with offshore oil (without 16x16 limit), or leave them in the water as they are, depending on the configuration. let's see if I have another idea that can be implemented quickly
Thank you for taking the time to investigate the problem.

Long time ago I tried making offshore oil its own resource. I was annoyed that Space Exploration would generate water-free planets whise main resource was offshore oil, and didn't try it again. It might still be a good option, maybe something else can be done about SE.

another thought: I would separate the offshore oil and Cargo Ships in separate mods. these are diffent domains. then there is also no trouble and a mod pack easily swap/disable/enable resource mods..