“Navy spokeswoman Kelly Wirfel said several sailors on watch at Naval Station Norfolk in Virginia briefly saw the person Monday in the water near the secured piers.”
https://www.stripes.com/news/navy/navy-scuba-diver-appears-to-have-breached-barrier-at-norfolk-1.480783#.WX-0x4jyu00
Ping the sonar, that’ll fix ‘em.