Over the years I've logged thousands of hours navigating Chesapeake Bay at night. During that time I've experienced many, many things that can be somewhat frightening, the least of which is tangling up a crab pot in the prop. Commercial traffic at night is fairly heavy in the bay's upper reaches, mainly north of the Chesapeake Bay Bridges at Sandy Point. Lots of barges, both towed and pushed, some as far north as Havre de Grace.
If you're out in the bay during the July 4th fireworks displays, you can often watch a half-dozen at the same time, which is really neat. Another form of fireworks that I wasn't prepared for came from Aberdeen Proving Ground when they had a night-firing exercise using tracer ammunition. Kind of scary hearing a massive boom, then watching a brilliant, red meteor soar 15 miles up the bay toward Spetiua Island and explode.
In the middle bay near Solomons one stormy night I encountered a tug towing a barge near the mouth of the Patuxent River. All of the sudden, the tug turned off it's towing lights, made a U-turn right in front of me, and headed back up the bay. The barge, however, was still there - just floating free with one tiny light that you could barely see. It almost appeared to be a kerosene lantern. The was a guy standing next to the lantern holding a flashlight and waving us off. About 10 minutes later, another tug from somewhere down south hooked up a towing cable to the barge, turned on his tow lights, and headed south. I later discovered this is not an uncommon practice.
The closest bad encounter I had was near Tilghman Island at about midnight. My wife and I had been up the Choptank at Oxford, visiting with my cousin, and we all had dinner at an upscale restaurant that had no prices on the menu. (He insisted on buying and I didn't argue the point.) We got underway about 7 p.m.. there was a brilliant full moon and I decided to sail downriver, then head north and spend the night anchored in the lee of Poplar Island. I was nearly 3/4-mile west of Tilghman Island when I turned north, the moon was beginning to set and we were sailing very comfortably at about 6-knots. My wife hates sailing at night, she was petrified. All of the sudden, just 50-feet from the bow, hundreds of pound-net stakes came into view. I swerved to starboard, rounded up and the boat stopped about 6 inches from the stakes. I fired up the engine, turned on the spotlight, eased away from the net and motor-sailed out into the main channel. There were no lights on the net at all.
Unfortunately, there are lots of unmarked pound nets and old pound net stakes throughout the Chesapeake's middle and lower reaches. Additionally, there are some unmarked U.S. Naval Target Ships in locations near Point Lookout, Smith Point and Tangier Island, ships that have been blasted away to where there is nothing visible above the surface, but just a few inches below the surface those rusted, steel beams can easily rip the bottom out of any vessel of any size. One that immediately comes to mind is the San Marcos Wreck, which many years ago was a favored fishing spot for catching big flounder, weakfish and blowfish. There used to be a marker buoy there, but it was removed about 20 years ago.
While I still love sailing at night, I try to avoid it now - too many close calls. I hope to install 3G Broadband Radar in the next few months, which will at least allow me to see the things above the water.