The upper limit calculation is a set of formulas, not a specific fixed value. In other words, when the sailor's ability reaches a certain range, its ability will be greatly reduced. For example, for every 1000 ability, the inflation time of 1 s can be reduced, which means 1000 ability. And if it is 4000 capacity, the inflation time per 100 capacity may be only 0.0 1 second.
There is never an absolute upper limit. If you have an absolutely high attribute (such as 9000), you will find that the effect still exists. Of course, no one can reach such a high level.
Generally speaking, it is normal to rise and fall about 2 100, and the difference will not exceed plus or minus 10 second. High ability does have an effect, but the later the effect will be lower and lower until you can't tell it with the naked eye.
I have already said the actual test data above. If I use very BT data, there will definitely be a difference in the appearance time. The normal time is as follows:
nationality
Country a (USN)
E country (HMS)
Country p (IJN)
Country g (KM)
Model (SS3)
Barracuda class
P-level
Haida type 6A
U boat type 7C
Maximum surface speed
37
36
39
40
Maximum submarine time
2'35"
2'30"
2'40"
2'35"
Re-diving time (air replenishment time)
1'30"
1'35"
1'40"
1'30"