I have a question about an app to see when a ship will pass by

or Ship Fan software. basically I want to take pictures of ships going on the Chesapeake Bay. I live about an hour -2 hours away from the bay bridge/Sandy point state park. would be great if there was an app that could tell me when a ship was going to pass by Sandy point heading for a port or leave the Baltimore Harbor or Annapolis for the open seas and give me time to get there

Try this.

MarineTraffic: Global Ship Tracking Intelligence | AIS Marine Traffic

Also https://www.vesselfinder.com/

Though you probably won’t be able to get very advanced notice of sailing schedules. You’ll be able to pick out specific ships. It’s not like airlines where arrivals and departures are publicly available and widely published. You may have to do a little bit of digging to learn consistent schedules of the ships in your area.

You could use Marine Traffic’s app and watch Cape Henry. Majority of Baltimore’s traffic passes the Cape 12 hours before arrival, less to your viewing spot and varies according to vessel speed, you will soon get a feel for when to be on the spot.

Save the ship in the app, and watch her in Baltimore, it’s a couple hours from sailing to the bay bridge, again varying. Another variable bulkers and tankers can transit any time. Container ships and Car Carriers plan arrivals according to labor start times that means overnight northbound transits early morning starts. Some work quickly start 7 or 8 am sail south bound late afternoon. You will soon get a feel for it.

Simular plan works Bay Bridge Anchorage and C&D canal, canal very few ocean vessels mostly tugs