That's the same number of total expulsions for drug policy violations in each of the last two calendar years.
Synthetic marijuana can be purchased legally but is banned by the Defense Department and the Navy. The Naval Criminal Investigative Service is leading an investigation at the academy.
The academy has been trying to raise awareness about a growing trend of fake marijuana use. The superintendent and commandant have addressed the issue at school-wide forums. The academy says it also has increased computer monitoring of common synthetic drug websites.