Talk:Type 4 Passive Sonar/@comment-29843077-20161215110346/@comment-85.233.202.3-20161215115716

I think the most important difference is that it's easier to achieve OASW with T4. A mere 2 (or 4) point in ASW can represent several levels, especially for DDs, and in some cases the ship would need to be ringed be able to perform OASW without T4.