It is now December. My NI DPO Unlimited expired this May 2019.
In the past 5 years I have 30 days DP sea-time.
Is the 5 day DP Revalidation course sufficient for renewal: https://www.mptusa.com/course/773-Dynamic-Positioning-Revalidation
If you get your application in before the end of December, yes. After that I think you need to start over at the beginning.
Thanks