We are going to make a few assumptions:

1) This is not specialized training associated with a particular weapon system.

2) This is not combined military training with coalition or foreign military partners associated with security assistance.

Yes, O&M funds are the appropriation used to fund most training requirements. References: DoD Financial Management Regulation Vol 2A, chapter 3, GAO Red Book Principles of Federal Appropriations Law: Ch 4, B.2.a. for purpose and Ch 5.B.5 for time. You may also have a Navy regulation that provides more specific guidance on use of Navy appropriations.

You can search the AAP site with terms such as "training" and "funds" to identify answers to similar questions that might have details closer to your specific scenario.

That said, we strongly suggest you ask your financial activity to ensure the specifics of your training including severable services and bona fide need issues have been discussed.