The public marine channels are usually controlled by Sector out of Curtis Bay,
To farther add to maus92's comments.
You should have received some Broadcast Notice to Mariners broadcasr either scheduled or random ones. The ones that repeat are recorded on Rescue 21 to be able to go out many times.
Sector has scheduled broadcast Notice to mariners in morning and evening, but can't remember the times. Plus the are on UTC times and shift for local times. Going forward from memory the morning broadcast is something like 8 or 8:30 AM during Daylight Savings Time. Night time broadcast is something like 9:30 PM DST.
Station Ocean City falls under Sector Maryland NCR command.
Sector has a 24/7 radio watch on channel 16 and various CG channels. They also have personal to plan and execute search and rescue cases, plus anything else required by CG like fuel spills or large vessel issues like engine operational issues.
Station most likely doesn't have a 24/7 watch with Sector having it. The duty ready boat crews can sleep at night when not required and if they are needed Sector will alert then if they need to get a boat underway.
Radio guard for underway CG small boats maybe controlled by their station. Many times Sector will handle radio guard duties. A lot Stations are short staffed and have no one to run the radio when boat gets underway.