Submarine survivability

[el cid again]

It appears too easy to sink submarines.

Adding durability only makes production problems worse - at least for Japan (the Allies don't exactly produce in the same sense).

I have an idea we can tamper with DC and mitigate this issue - with a single exception - the smallest DC is also a bomb - we can use a K factor to make DC less effective. We keep load cost the same - but reduce effect. This will preserve pattern size data research and make reports look good - but be less likely to damage or sink - as should be the case. The question is - how big is K?

K - a contant - is a fraction - something like 1/3 or 1/2 in this case - as a first pass guess.

Changing it is fast and easy - only a few devices need changes.

The one anomoly is probably not important - the smallest case is not very effective anyway.