Daily, from 6:00 AM to 10:00 AM, the bridge opens at the top of each hour:
Daily from 11:15 AM to 6:15 PM, the bridge opens 15 minutes past each hour:
After 6:15 PM, the bridge will open on-demand from marine traffic by calling the bridge keeper’s office on marine channel 13. The schedule and duration of openings will vary depending on weather conditions, harbor congestion and vessel size. By law, marine traffic has priority over vehicular traffic.
Official details here.